diff --git a/libcxx/docs/ReleaseNotes.rst b/libcxx/docs/ReleaseNotes.rst
--- a/libcxx/docs/ReleaseNotes.rst
+++ b/libcxx/docs/ReleaseNotes.rst
@@ -101,6 +101,14 @@
 ABI Affecting Changes
 ---------------------
 
+- Symbols for ``std::allocator_arg``, ``std::defer_lock``, ``std::try_to_lock``, ``std::adopt_lock``, and
+  ``std::piecewise_construct`` have been removed from the built library. Under most circumstances, user code
+  should not have been relying on those symbols anyway since those are empty classes and the compiler does
+  not generate an undefined reference unless the address of the object is taken. However, this is an ABI break
+  if the address of one of these objects has been taken in code compiled as C++03, since in those cases the
+  objects were marked as defined in the shared library. In other Standard modes, this should never be a problem
+  since those objects were defined in the headers as ``constexpr``.
+
 Build System Changes
 --------------------
 
diff --git a/libcxx/include/__memory/allocator_arg_t.h b/libcxx/include/__memory/allocator_arg_t.h
--- a/libcxx/include/__memory/allocator_arg_t.h
+++ b/libcxx/include/__memory/allocator_arg_t.h
@@ -25,14 +25,10 @@
 
 struct _LIBCPP_TEMPLATE_VIS allocator_arg_t { explicit allocator_arg_t() = default; };
 
-#if defined(_LIBCPP_BUILDING_LIBRARY)
-extern _LIBCPP_EXPORTED_FROM_ABI const allocator_arg_t allocator_arg;
-#elif !defined(_LIBCPP_CXX03_LANG)
-/* inline */ constexpr allocator_arg_t allocator_arg = allocator_arg_t();
-#endif
-
 #ifndef _LIBCPP_CXX03_LANG
 
+/* inline */ constexpr allocator_arg_t allocator_arg = allocator_arg_t();
+
 // allocator construction
 
 template <class _Tp, class _Alloc, class ..._Args>
diff --git a/libcxx/include/__mutex_base b/libcxx/include/__mutex_base
--- a/libcxx/include/__mutex_base
+++ b/libcxx/include/__mutex_base
@@ -66,14 +66,10 @@
 struct _LIBCPP_TYPE_VIS try_to_lock_t { explicit try_to_lock_t() = default; };
 struct _LIBCPP_TYPE_VIS adopt_lock_t { explicit adopt_lock_t() = default; };
 
-#  if defined(_LIBCPP_BUILDING_LIBRARY)
-extern _LIBCPP_EXPORTED_FROM_ABI const defer_lock_t defer_lock;
-extern _LIBCPP_EXPORTED_FROM_ABI const try_to_lock_t try_to_lock;
-extern _LIBCPP_EXPORTED_FROM_ABI const adopt_lock_t adopt_lock;
-#  elif !defined(_LIBCPP_CXX03_LANG)
-/* inline */ constexpr defer_lock_t defer_lock = defer_lock_t();
+#  if !defined(_LIBCPP_CXX03_LANG)
+/* inline */ constexpr defer_lock_t defer_lock   = defer_lock_t();
 /* inline */ constexpr try_to_lock_t try_to_lock = try_to_lock_t();
-/* inline */ constexpr adopt_lock_t adopt_lock = adopt_lock_t();
+/* inline */ constexpr adopt_lock_t adopt_lock   = adopt_lock_t();
 #  endif
 
 template <class _Mutex>
diff --git a/libcxx/include/__utility/piecewise_construct.h b/libcxx/include/__utility/piecewise_construct.h
--- a/libcxx/include/__utility/piecewise_construct.h
+++ b/libcxx/include/__utility/piecewise_construct.h
@@ -19,9 +19,7 @@
 
 struct _LIBCPP_TEMPLATE_VIS piecewise_construct_t { explicit piecewise_construct_t() = default; };
 
-#if defined(_LIBCPP_BUILDING_LIBRARY)
-extern _LIBCPP_EXPORTED_FROM_ABI const piecewise_construct_t piecewise_construct;
-#elif !defined(_LIBCPP_CXX03_LANG)
+#if !defined(_LIBCPP_CXX03_LANG)
 /* inline */ constexpr piecewise_construct_t piecewise_construct = piecewise_construct_t();
 #endif
 
diff --git a/libcxx/lib/abi/CHANGELOG.TXT b/libcxx/lib/abi/CHANGELOG.TXT
--- a/libcxx/lib/abi/CHANGELOG.TXT
+++ b/libcxx/lib/abi/CHANGELOG.TXT
@@ -16,6 +16,38 @@
 Version 17.0
 ------------
 
+* [libc++] Remove symbols for a std::allocator_arg & friends from the dylib
+
+  This patch removes the symbols defined in the library for std::allocator_arg,
+  std::defer_lock, std::try_to_lock, std::adopt_lock, and std::piecewise_construct.
+  Those were defined in the library because we provided them in C++03 as an
+  extension, and in C++03 it was impossible to define them as `constexpr`
+  variables, as required by the Standard.
+
+  This is technically an ABI break since we are removing symbols from the
+  library. However, in practice, only programs compiled in C++03 mode that
+  take the address of those objects (or pass them as a reference) will have
+  an undefined ref to those symbols. In practice, this is expected to be
+  rare. First, those are C++11 features that we happen to provide in C++03,
+  and only the C++03 definition can potentially lead to code referencing
+  the dylib definition. So any code that is using these objects but compiling
+  in C++11 mode (as they should) is not at risk. Second, all uses of these
+  types in the library is done by passing those types by value to a function
+  that can get inlined. Since they are empty types, the compiler won't
+  generate an undefined reference if passed by value, since there's nothing
+  to pass anyway.
+
+  Long story short, the risk for code actually containing an undefined
+  reference to one of these types is rather small (but non-zero).
+
+  All platforms
+  -------------
+  Symbol removed: _ZNSt3__110adopt_lockE
+  Symbol removed: _ZNSt3__110defer_lockE
+  Symbol removed: _ZNSt3__111try_to_lockE
+  Symbol removed: _ZNSt3__113allocator_argE
+  Symbol removed: _ZNSt3__119piecewise_constructE
+
 * [libc++] Remove explicit instantiations of __insertion_sort_incomplete and __sort5 from the dylib
 
   These instantiations were never visible, because they are only used in `__sort`, which is also explicitly
diff --git a/libcxx/lib/abi/arm64-apple-darwin.libcxxabi.v1.stable.exceptions.nonew.abilist b/libcxx/lib/abi/arm64-apple-darwin.libcxxabi.v1.stable.exceptions.nonew.abilist
--- a/libcxx/lib/abi/arm64-apple-darwin.libcxxabi.v1.stable.exceptions.nonew.abilist
+++ b/libcxx/lib/abi/arm64-apple-darwin.libcxxabi.v1.stable.exceptions.nonew.abilist
@@ -860,7 +860,6 @@
 {'is_defined': True, 'name': '__ZNSt3__110__time_putC2ERKNS_12basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEEE', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__110__time_putD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__110__time_putD2Ev', 'type': 'FUNC'}
-{'is_defined': True, 'name': '__ZNSt3__110adopt_lockE', 'size': 0, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '__ZNSt3__110ctype_base5alnumE', 'size': 0, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '__ZNSt3__110ctype_base5alphaE', 'size': 0, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '__ZNSt3__110ctype_base5blankE', 'size': 0, 'type': 'OBJECT'}
@@ -873,7 +872,6 @@
 {'is_defined': True, 'name': '__ZNSt3__110ctype_base5spaceE', 'size': 0, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '__ZNSt3__110ctype_base5upperE', 'size': 0, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '__ZNSt3__110ctype_base6xdigitE', 'size': 0, 'type': 'OBJECT'}
-{'is_defined': True, 'name': '__ZNSt3__110defer_lockE', 'size': 0, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '__ZNSt3__110istrstreamD0Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__110istrstreamD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__110istrstreamD2Ev', 'type': 'FUNC'}
@@ -917,7 +915,6 @@
 {'is_defined': True, 'name': '__ZNSt3__111timed_mutexC2Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__111timed_mutexD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__111timed_mutexD2Ev', 'type': 'FUNC'}
-{'is_defined': True, 'name': '__ZNSt3__111try_to_lockE', 'size': 0, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '__ZNSt3__112__do_nothingEPv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__112__get_sp_mutEPKv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__112__next_primeEm', 'type': 'FUNC'}
@@ -1081,7 +1078,6 @@
 {'is_defined': True, 'name': '__ZNSt3__112system_errorD0Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__112system_errorD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__112system_errorD2Ev', 'type': 'FUNC'}
-{'is_defined': True, 'name': '__ZNSt3__113allocator_argE', 'size': 0, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '__ZNSt3__113basic_filebufIcNS_11char_traitsIcEEE11__read_modeEv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__113basic_filebufIcNS_11char_traitsIcEEE12__write_modeEv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__113basic_filebufIcNS_11char_traitsIcEEE4openEPKcj', 'type': 'FUNC'}
@@ -1517,7 +1513,6 @@
 {'is_defined': True, 'name': '__ZNSt3__119basic_istringstreamIcNS_11char_traitsIcEENS_9allocatorIcEEEaSEOS5_', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__119basic_ostringstreamIcNS_11char_traitsIcEENS_9allocatorIcEEEaSEOS5_', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__119declare_no_pointersEPcm', 'type': 'FUNC'}
-{'is_defined': True, 'name': '__ZNSt3__119piecewise_constructE', 'size': 0, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '__ZNSt3__120__get_collation_nameEPKc', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__120__libcpp_atomic_waitEPVKNS_17__cxx_atomic_implIxNS_22__cxx_atomic_base_implIxEEEEx', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__120__libcpp_atomic_waitEPVKvx', 'type': 'FUNC'}
diff --git a/libcxx/lib/abi/powerpc-ibm-aix.libcxxabi.v1.stable.exceptions.nonew.abilist b/libcxx/lib/abi/powerpc-ibm-aix.libcxxabi.v1.stable.exceptions.nonew.abilist
--- a/libcxx/lib/abi/powerpc-ibm-aix.libcxxabi.v1.stable.exceptions.nonew.abilist
+++ b/libcxx/lib/abi/powerpc-ibm-aix.libcxxabi.v1.stable.exceptions.nonew.abilist
@@ -281,7 +281,6 @@
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110__time_putC2ERKNS_12basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEEE', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110__time_putD1Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110__time_putD2Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
-{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110adopt_lockE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110ctype_base5alnumE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110ctype_base5alphaE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110ctype_base5blankE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
@@ -294,7 +293,6 @@
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110ctype_base5spaceE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110ctype_base5upperE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110ctype_base6xdigitE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
-{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110defer_lockE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110istrstreamD0Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110istrstreamD1Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110istrstreamD2Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
@@ -324,7 +322,6 @@
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__111timed_mutexC2Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__111timed_mutexD1Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__111timed_mutexD2Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
-{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__111try_to_lockE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__112__do_nothingEPv', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__112__get_sp_mutEPKv', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__112__next_primeEm', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
@@ -412,7 +409,6 @@
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__112system_errorD0Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__112system_errorD1Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__112system_errorD2Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
-{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__113allocator_argE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__113random_deviceC1ERKNS_12basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEEE', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__113random_deviceC2ERKNS_12basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEEE', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__113random_deviceD1Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
@@ -552,7 +548,6 @@
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__119__shared_weak_countD2Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__119__thread_local_dataEv', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__119declare_no_pointersEPcm', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
-{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__119piecewise_constructE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__120__get_collation_nameEPKc', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__120__libcpp_atomic_waitEPVKNS_17__cxx_atomic_implIiNS_22__cxx_atomic_base_implIiEEEEi', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__120__libcpp_atomic_waitEPVKvi', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
diff --git a/libcxx/lib/abi/powerpc64-ibm-aix.libcxxabi.v1.stable.exceptions.nonew.abilist b/libcxx/lib/abi/powerpc64-ibm-aix.libcxxabi.v1.stable.exceptions.nonew.abilist
--- a/libcxx/lib/abi/powerpc64-ibm-aix.libcxxabi.v1.stable.exceptions.nonew.abilist
+++ b/libcxx/lib/abi/powerpc64-ibm-aix.libcxxabi.v1.stable.exceptions.nonew.abilist
@@ -281,7 +281,6 @@
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110__time_putC2ERKNS_12basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEEE', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110__time_putD1Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110__time_putD2Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
-{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110adopt_lockE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110ctype_base5alnumE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110ctype_base5alphaE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110ctype_base5blankE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
@@ -294,7 +293,6 @@
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110ctype_base5spaceE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110ctype_base5upperE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110ctype_base6xdigitE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
-{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110defer_lockE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110istrstreamD0Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110istrstreamD1Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__110istrstreamD2Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
@@ -324,7 +322,6 @@
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__111timed_mutexC2Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__111timed_mutexD1Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__111timed_mutexD2Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
-{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__111try_to_lockE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__112__do_nothingEPv', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__112__get_sp_mutEPKv', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__112__next_primeEm', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
@@ -412,7 +409,6 @@
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__112system_errorD0Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__112system_errorD1Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__112system_errorD2Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
-{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__113allocator_argE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__113random_deviceC1ERKNS_12basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEEE', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__113random_deviceC2ERKNS_12basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEEE', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__113random_deviceD1Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
@@ -552,7 +548,6 @@
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__119__shared_weak_countD2Ev', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__119__thread_local_dataEv', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__119declare_no_pointersEPcm', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
-{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__119piecewise_constructE', 'storage_mapping_class': 'RO', 'type': 'OBJECT'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__120__get_collation_nameEPKc', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__120__libcpp_atomic_waitEPVKNS_17__cxx_atomic_implIlNS_22__cxx_atomic_base_implIlEEEEl', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
 {'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__120__libcpp_atomic_waitEPVKvl', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
diff --git a/libcxx/lib/abi/x86_64-apple-darwin.libcxxabi.v1.stable.exceptions.nonew.abilist b/libcxx/lib/abi/x86_64-apple-darwin.libcxxabi.v1.stable.exceptions.nonew.abilist
--- a/libcxx/lib/abi/x86_64-apple-darwin.libcxxabi.v1.stable.exceptions.nonew.abilist
+++ b/libcxx/lib/abi/x86_64-apple-darwin.libcxxabi.v1.stable.exceptions.nonew.abilist
@@ -860,7 +860,6 @@
 {'is_defined': True, 'name': '__ZNSt3__110__time_putC2ERKNS_12basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEEE', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__110__time_putD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__110__time_putD2Ev', 'type': 'FUNC'}
-{'is_defined': True, 'name': '__ZNSt3__110adopt_lockE', 'size': 0, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '__ZNSt3__110ctype_base5alnumE', 'size': 0, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '__ZNSt3__110ctype_base5alphaE', 'size': 0, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '__ZNSt3__110ctype_base5blankE', 'size': 0, 'type': 'OBJECT'}
@@ -873,7 +872,6 @@
 {'is_defined': True, 'name': '__ZNSt3__110ctype_base5spaceE', 'size': 0, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '__ZNSt3__110ctype_base5upperE', 'size': 0, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '__ZNSt3__110ctype_base6xdigitE', 'size': 0, 'type': 'OBJECT'}
-{'is_defined': True, 'name': '__ZNSt3__110defer_lockE', 'size': 0, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '__ZNSt3__110istrstreamD0Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__110istrstreamD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__110istrstreamD2Ev', 'type': 'FUNC'}
@@ -917,7 +915,6 @@
 {'is_defined': True, 'name': '__ZNSt3__111timed_mutexC2Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__111timed_mutexD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__111timed_mutexD2Ev', 'type': 'FUNC'}
-{'is_defined': True, 'name': '__ZNSt3__111try_to_lockE', 'size': 0, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '__ZNSt3__112__do_nothingEPv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__112__get_sp_mutEPKv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__112__next_primeEm', 'type': 'FUNC'}
@@ -1081,7 +1078,6 @@
 {'is_defined': True, 'name': '__ZNSt3__112system_errorD0Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__112system_errorD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__112system_errorD2Ev', 'type': 'FUNC'}
-{'is_defined': True, 'name': '__ZNSt3__113allocator_argE', 'size': 0, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '__ZNSt3__113basic_filebufIcNS_11char_traitsIcEEE11__read_modeEv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__113basic_filebufIcNS_11char_traitsIcEEE12__write_modeEv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__113basic_filebufIcNS_11char_traitsIcEEE4openEPKcj', 'type': 'FUNC'}
@@ -1517,7 +1513,6 @@
 {'is_defined': True, 'name': '__ZNSt3__119basic_istringstreamIcNS_11char_traitsIcEENS_9allocatorIcEEEaSEOS5_', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__119basic_ostringstreamIcNS_11char_traitsIcEENS_9allocatorIcEEEaSEOS5_', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__119declare_no_pointersEPcm', 'type': 'FUNC'}
-{'is_defined': True, 'name': '__ZNSt3__119piecewise_constructE', 'size': 0, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '__ZNSt3__120__get_collation_nameEPKc', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__120__libcpp_atomic_waitEPVKNS_17__cxx_atomic_implIxNS_22__cxx_atomic_base_implIxEEEEx', 'type': 'FUNC'}
 {'is_defined': True, 'name': '__ZNSt3__120__libcpp_atomic_waitEPVKvx', 'type': 'FUNC'}
diff --git a/libcxx/lib/abi/x86_64-unknown-freebsd.libcxxabi.v1.stable.exceptions.nonew.abilist b/libcxx/lib/abi/x86_64-unknown-freebsd.libcxxabi.v1.stable.exceptions.nonew.abilist
--- a/libcxx/lib/abi/x86_64-unknown-freebsd.libcxxabi.v1.stable.exceptions.nonew.abilist
+++ b/libcxx/lib/abi/x86_64-unknown-freebsd.libcxxabi.v1.stable.exceptions.nonew.abilist
@@ -555,7 +555,6 @@
 {'is_defined': True, 'name': '_ZNSt3__110__time_putC2ERKNS_12basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEEE', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__110__time_putD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__110__time_putD2Ev', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__110adopt_lockE', 'size': 1, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__110ctype_base5alnumE', 'size': 8, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__110ctype_base5alphaE', 'size': 8, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__110ctype_base5blankE', 'size': 8, 'type': 'OBJECT'}
@@ -568,7 +567,6 @@
 {'is_defined': True, 'name': '_ZNSt3__110ctype_base5spaceE', 'size': 8, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__110ctype_base5upperE', 'size': 8, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__110ctype_base6xdigitE', 'size': 8, 'type': 'OBJECT'}
-{'is_defined': True, 'name': '_ZNSt3__110defer_lockE', 'size': 1, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__110istrstreamD0Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__110istrstreamD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__110istrstreamD2Ev', 'type': 'FUNC'}
@@ -612,7 +610,6 @@
 {'is_defined': True, 'name': '_ZNSt3__111timed_mutexC2Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__111timed_mutexD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__111timed_mutexD2Ev', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__111try_to_lockE', 'size': 1, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__112__do_nothingEPv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__112__get_sp_mutEPKv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__112__next_primeEm', 'type': 'FUNC'}
@@ -776,7 +773,6 @@
 {'is_defined': True, 'name': '_ZNSt3__112system_errorD0Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__112system_errorD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__112system_errorD2Ev', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__113allocator_argE', 'size': 1, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__113basic_filebufIcNS_11char_traitsIcEEE11__read_modeEv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__113basic_filebufIcNS_11char_traitsIcEEE12__write_modeEv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__113basic_filebufIcNS_11char_traitsIcEEE4openEPKcj', 'type': 'FUNC'}
@@ -1212,7 +1208,6 @@
 {'is_defined': True, 'name': '_ZNSt3__119basic_istringstreamIcNS_11char_traitsIcEENS_9allocatorIcEEEaSEOS5_', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__119basic_ostringstreamIcNS_11char_traitsIcEENS_9allocatorIcEEEaSEOS5_', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__119declare_no_pointersEPcm', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__119piecewise_constructE', 'size': 1, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__120__get_collation_nameEPKc', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__120__libcpp_atomic_waitEPVKNS_17__cxx_atomic_implIlNS_22__cxx_atomic_base_implIlEEEEl', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__120__libcpp_atomic_waitEPVKvl', 'type': 'FUNC'}
diff --git a/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.exceptions.nonew.abilist b/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.exceptions.nonew.abilist
--- a/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.exceptions.nonew.abilist
+++ b/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.exceptions.nonew.abilist
@@ -553,7 +553,6 @@
 {'is_defined': True, 'name': '_ZNSt3__110__time_putC2ERKNS_12basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEEE', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__110__time_putD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__110__time_putD2Ev', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__110adopt_lockE', 'size': 1, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__110ctype_base5alnumE', 'size': 2, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__110ctype_base5alphaE', 'size': 2, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__110ctype_base5blankE', 'size': 2, 'type': 'OBJECT'}
@@ -566,7 +565,6 @@
 {'is_defined': True, 'name': '_ZNSt3__110ctype_base5spaceE', 'size': 2, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__110ctype_base5upperE', 'size': 2, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__110ctype_base6xdigitE', 'size': 2, 'type': 'OBJECT'}
-{'is_defined': True, 'name': '_ZNSt3__110defer_lockE', 'size': 1, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__110istrstreamD0Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__110istrstreamD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__110istrstreamD2Ev', 'type': 'FUNC'}
@@ -610,7 +608,6 @@
 {'is_defined': True, 'name': '_ZNSt3__111timed_mutexC2Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__111timed_mutexD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__111timed_mutexD2Ev', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__111try_to_lockE', 'size': 1, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__112__do_nothingEPv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__112__get_sp_mutEPKv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__112__next_primeEm', 'type': 'FUNC'}
@@ -774,7 +771,6 @@
 {'is_defined': True, 'name': '_ZNSt3__112system_errorD0Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__112system_errorD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__112system_errorD2Ev', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__113allocator_argE', 'size': 1, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__113basic_filebufIcNS_11char_traitsIcEEE11__read_modeEv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__113basic_filebufIcNS_11char_traitsIcEEE12__write_modeEv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__113basic_filebufIcNS_11char_traitsIcEEE4openEPKcj', 'type': 'FUNC'}
@@ -1210,7 +1206,6 @@
 {'is_defined': True, 'name': '_ZNSt3__119basic_istringstreamIcNS_11char_traitsIcEENS_9allocatorIcEEEaSEOS5_', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__119basic_ostringstreamIcNS_11char_traitsIcEENS_9allocatorIcEEEaSEOS5_', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__119declare_no_pointersEPcm', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__119piecewise_constructE', 'size': 1, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__120__get_collation_nameEPKc', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__120__libcpp_atomic_waitEPVKNS_17__cxx_atomic_implIiNS_22__cxx_atomic_base_implIiEEEEi', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__120__libcpp_atomic_waitEPVKvi', 'type': 'FUNC'}
diff --git a/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.noexceptions.nonew.abilist b/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.noexceptions.nonew.abilist
--- a/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.noexceptions.nonew.abilist
+++ b/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.noexceptions.nonew.abilist
@@ -525,7 +525,6 @@
 {'is_defined': True, 'name': '_ZNSt3__110__time_putC2ERKNS_12basic_stringIcNS_11char_traitsIcEENS_9allocatorIcEEEE', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__110__time_putD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__110__time_putD2Ev', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__110adopt_lockE', 'size': 1, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__110ctype_base5alnumE', 'size': 2, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__110ctype_base5alphaE', 'size': 2, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__110ctype_base5blankE', 'size': 2, 'type': 'OBJECT'}
@@ -538,7 +537,6 @@
 {'is_defined': True, 'name': '_ZNSt3__110ctype_base5spaceE', 'size': 2, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__110ctype_base5upperE', 'size': 2, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__110ctype_base6xdigitE', 'size': 2, 'type': 'OBJECT'}
-{'is_defined': True, 'name': '_ZNSt3__110defer_lockE', 'size': 1, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__110istrstreamD0Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__110istrstreamD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__110istrstreamD2Ev', 'type': 'FUNC'}
@@ -582,7 +580,6 @@
 {'is_defined': True, 'name': '_ZNSt3__111timed_mutexC2Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__111timed_mutexD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__111timed_mutexD2Ev', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__111try_to_lockE', 'size': 1, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__112__do_nothingEPv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__112__get_sp_mutEPKv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__112__next_primeEm', 'type': 'FUNC'}
@@ -746,7 +743,6 @@
 {'is_defined': True, 'name': '_ZNSt3__112system_errorD0Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__112system_errorD1Ev', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__112system_errorD2Ev', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__113allocator_argE', 'size': 1, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__113basic_filebufIcNS_11char_traitsIcEEE11__read_modeEv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__113basic_filebufIcNS_11char_traitsIcEEE12__write_modeEv', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__113basic_filebufIcNS_11char_traitsIcEEE4openEPKcj', 'type': 'FUNC'}
@@ -1182,7 +1178,6 @@
 {'is_defined': True, 'name': '_ZNSt3__119basic_istringstreamIcNS_11char_traitsIcEENS_9allocatorIcEEEaSEOS5_', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__119basic_ostringstreamIcNS_11char_traitsIcEENS_9allocatorIcEEEaSEOS5_', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__119declare_no_pointersEPcm', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__119piecewise_constructE', 'size': 1, 'type': 'OBJECT'}
 {'is_defined': True, 'name': '_ZNSt3__120__get_collation_nameEPKc', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__120__libcpp_atomic_waitEPVKNS_17__cxx_atomic_implIiNS_22__cxx_atomic_base_implIiEEEEi', 'type': 'FUNC'}
 {'is_defined': True, 'name': '_ZNSt3__120__libcpp_atomic_waitEPVKvi', 'type': 'FUNC'}
diff --git a/libcxx/src/CMakeLists.txt b/libcxx/src/CMakeLists.txt
--- a/libcxx/src/CMakeLists.txt
+++ b/libcxx/src/CMakeLists.txt
@@ -58,7 +58,6 @@
   system_error.cpp
   thread.cpp
   typeinfo.cpp
-  utility.cpp
   valarray.cpp
   variant.cpp
   vector.cpp
diff --git a/libcxx/src/memory.cpp b/libcxx/src/memory.cpp
--- a/libcxx/src/memory.cpp
+++ b/libcxx/src/memory.cpp
@@ -25,8 +25,6 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-const allocator_arg_t allocator_arg = allocator_arg_t();
-
 bad_weak_ptr::~bad_weak_ptr() noexcept {}
 
 const char*
diff --git a/libcxx/src/mutex.cpp b/libcxx/src/mutex.cpp
--- a/libcxx/src/mutex.cpp
+++ b/libcxx/src/mutex.cpp
@@ -26,10 +26,6 @@
 
 #ifndef _LIBCPP_HAS_NO_THREADS
 
-const defer_lock_t  defer_lock{};
-const try_to_lock_t try_to_lock{};
-const adopt_lock_t  adopt_lock{};
-
 // ~mutex is defined elsewhere
 
 void
diff --git a/libcxx/src/utility.cpp b/libcxx/src/utility.cpp
deleted file mode 100644
--- a/libcxx/src/utility.cpp
+++ /dev/null
@@ -1,15 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#include <utility>
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-const piecewise_construct_t piecewise_construct{};
-
-_LIBCPP_END_NAMESPACE_STD