diff --git a/libcxx/docs/index.rst b/libcxx/docs/index.rst
--- a/libcxx/docs/index.rst
+++ b/libcxx/docs/index.rst
@@ -100,7 +100,7 @@
 
 The following minimum compiler versions are strongly recommended.
 
-* Clang 3.5 and above
+* Clang 4.0 and above
 * GCC 5.0 and above.
 
 The C++03 dialect is only supported for Clang compilers.
diff --git a/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t.pass.cpp b/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t.pass.cpp
--- a/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t.pass.cpp
+++ b/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t.pass.cpp
@@ -11,9 +11,6 @@
 // asan and msan will not call the new handler.
 // UNSUPPORTED: sanitizer-new-delete
 
-// FIXME change this to XFAIL.
-// UNSUPPORTED: no-aligned-allocation && !gcc
-
 // Aligned allocation was not provided before macosx10.14 and as a result we
 // get availability errors when the deployment target is older than macosx10.14.
 // However, AppleClang 10 (and older) don't trigger availability errors, and
diff --git a/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_nothrow.pass.cpp b/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_nothrow.pass.cpp
--- a/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_nothrow.pass.cpp
+++ b/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_nothrow.pass.cpp
@@ -11,9 +11,6 @@
 // asan and msan will not call the new handler.
 // UNSUPPORTED: sanitizer-new-delete
 
-// FIXME turn this into an XFAIL
-// UNSUPPORTED: no-aligned-allocation && !gcc
-
 // Aligned allocation was not provided before macosx10.14 and as a result we
 // get availability errors when the deployment target is older than macosx10.14.
 // However, AppleClang 10 (and older) don't trigger availability errors, and
diff --git a/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_nothrow_replace.pass.cpp b/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_nothrow_replace.pass.cpp
--- a/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_nothrow_replace.pass.cpp
+++ b/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_nothrow_replace.pass.cpp
@@ -31,8 +31,6 @@
 // XFAIL: (apple-clang-9 || apple-clang-10) && with_system_cxx_lib=macosx10.8
 // XFAIL: (apple-clang-9 || apple-clang-10) && with_system_cxx_lib=macosx10.7
 
-// XFAIL: no-aligned-allocation && !gcc
-
 // On Windows libc++ doesn't provide its own definitions for new/delete
 // but instead depends on the ones in VCRuntime. However VCRuntime does not
 // yet provide aligned new/delete definitions so this test fails.
diff --git a/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_replace.pass.cpp b/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_replace.pass.cpp
--- a/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_replace.pass.cpp
+++ b/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.array/new_align_val_t_replace.pass.cpp
@@ -9,9 +9,6 @@
 // UNSUPPORTED: c++98, c++03, c++11, c++14
 // UNSUPPORTED: sanitizer-new-delete
 
-// NOTE: GCC doesn't provide the -faligned-allocation flag to test for
-// XFAIL: no-aligned-allocation && !gcc
-
 // test operator new replacement
 
 #include <new>
diff --git a/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t.pass.cpp b/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t.pass.cpp
--- a/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t.pass.cpp
+++ b/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t.pass.cpp
@@ -33,9 +33,6 @@
 // asan and msan will not call the new handler.
 // UNSUPPORTED: sanitizer-new-delete
 
-// FIXME turn this into an XFAIL
-// UNSUPPORTED: no-aligned-allocation && !gcc
-
 // On Windows libc++ doesn't provide its own definitions for new/delete
 // but instead depends on the ones in VCRuntime. However VCRuntime does not
 // yet provide aligned new/delete definitions so this test fails to compile/link.
diff --git a/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_nothrow.pass.cpp b/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_nothrow.pass.cpp
--- a/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_nothrow.pass.cpp
+++ b/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_nothrow.pass.cpp
@@ -33,9 +33,6 @@
 // asan and msan will not call the new handler.
 // UNSUPPORTED: sanitizer-new-delete
 
-// FIXME turn this into an XFAIL
-// UNSUPPORTED: no-aligned-allocation && !gcc
-
 // On Windows libc++ doesn't provide its own definitions for new/delete
 // but instead depends on the ones in VCRuntime. However VCRuntime does not
 // yet provide aligned new/delete definitions so this test fails to compile/link.
diff --git a/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_nothrow_replace.pass.cpp b/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_nothrow_replace.pass.cpp
--- a/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_nothrow_replace.pass.cpp
+++ b/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_nothrow_replace.pass.cpp
@@ -31,9 +31,6 @@
 // XFAIL: (apple-clang-9 || apple-clang-10) && with_system_cxx_lib=macosx10.8
 // XFAIL: (apple-clang-9 || apple-clang-10) && with_system_cxx_lib=macosx10.7
 
-// NOTE: gcc doesn't provide -faligned-allocation flag to test for
-// XFAIL: no-aligned-allocation && !gcc
-
 // On Windows libc++ doesn't provide its own definitions for new/delete
 // but instead depends on the ones in VCRuntime. However VCRuntime does not
 // yet provide aligned new/delete definitions so this test fails.
diff --git a/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_replace.pass.cpp b/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_replace.pass.cpp
--- a/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_replace.pass.cpp
+++ b/libcxx/test/std/language.support/support.dynamic/new.delete/new.delete.single/new_align_val_t_replace.pass.cpp
@@ -9,9 +9,6 @@
 // UNSUPPORTED: c++98, c++03, c++11, c++14
 // UNSUPPORTED: sanitizer-new-delete
 
-// NOTE: GCC doesn't provide a -faligned-allocation flag
-// XFAIL: no-aligned-allocation && !gcc
-
 // test operator new replacement
 
 #include <new>
diff --git a/libcxx/utils/libcxx/test/config.py b/libcxx/utils/libcxx/test/config.py
--- a/libcxx/utils/libcxx/test/config.py
+++ b/libcxx/utils/libcxx/test/config.py
@@ -452,10 +452,6 @@
 
         if self.cxx.hasCompileFlag('-faligned-allocation'):
             self.config.available_features.add('-faligned-allocation')
-        else:
-            # FIXME remove this once more than just clang-4.0 support
-            # C++17 aligned allocation.
-            self.config.available_features.add('no-aligned-allocation')
 
         if self.cxx.hasCompileFlag('-fdelayed-template-parsing'):
             self.config.available_features.add('fdelayed-template-parsing')