Index: libcxx/include/__config
===================================================================
--- libcxx/include/__config
+++ libcxx/include/__config
@@ -328,6 +328,28 @@
 #  define _LIBCPP_NO_CFI
 #endif
 
+#if __ISO_C_VISIBLE >= 2011 || __cplusplus >= 201103L
+#  if defined(__FreeBSD__)
+#    define _LIBCPP_HAS_QUICK_EXIT
+#    define _LIBCPP_HAS_C11_FEATURES
+#  elif defined(__Fuchsia__)
+#    define _LIBCPP_HAS_QUICK_EXIT
+#    define _LIBCPP_HAS_C11_FEATURES
+#  elif defined(__linux__)
+#    if !defined(_LIBCPP_HAS_MUSL_LIBC)
+#      if _LIBCPP_GLIBC_PREREQ(2, 15) || defined(__BIONIC__)
+#        define _LIBCPP_HAS_QUICK_EXIT
+#      endif
+#      if _LIBCPP_GLIBC_PREREQ(2, 17)
+#        define _LIBCPP_HAS_C11_FEATURES
+#      endif
+#    else // defined(_LIBCPP_HAS_MUSL_LIBC)
+#      define _LIBCPP_HAS_QUICK_EXIT
+#      define _LIBCPP_HAS_C11_FEATURES
+#    endif
+#  endif // __linux__
+#endif
+
 #if defined(_LIBCPP_COMPILER_CLANG)
 
 // _LIBCPP_ALTERNATE_STRING_LAYOUT is an old name for
@@ -430,28 +452,6 @@
 #define _LIBCPP_HAS_NO_VARIABLE_TEMPLATES
 #endif
 
-#if __ISO_C_VISIBLE >= 2011 || __cplusplus >= 201103L
-#  if defined(__FreeBSD__)
-#    define _LIBCPP_HAS_QUICK_EXIT
-#    define _LIBCPP_HAS_C11_FEATURES
-#  elif defined(__Fuchsia__)
-#    define _LIBCPP_HAS_QUICK_EXIT
-#    define _LIBCPP_HAS_C11_FEATURES
-#  elif defined(__linux__)
-#    if !defined(_LIBCPP_HAS_MUSL_LIBC)
-#      if _LIBCPP_GLIBC_PREREQ(2, 15) || defined(__BIONIC__)
-#        define _LIBCPP_HAS_QUICK_EXIT
-#      endif
-#      if _LIBCPP_GLIBC_PREREQ(2, 17)
-#        define _LIBCPP_HAS_C11_FEATURES
-#      endif
-#    else // defined(_LIBCPP_HAS_MUSL_LIBC)
-#      define _LIBCPP_HAS_QUICK_EXIT
-#      define _LIBCPP_HAS_C11_FEATURES
-#    endif
-#  endif // __linux__
-#endif
-
 #if !(__has_feature(cxx_noexcept))
 #define _LIBCPP_HAS_NO_NOEXCEPT
 #endif
Index: libcxx/test/std/depr/depr.c.headers/float_h.pass.cpp
===================================================================
--- libcxx/test/std/depr/depr.c.headers/float_h.pass.cpp
+++ libcxx/test/std/depr/depr.c.headers/float_h.pass.cpp
@@ -25,7 +25,7 @@
 #error FLT_RADIX not defined
 #endif
 
-#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES)
+#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES) && 0
 #ifndef FLT_HAS_SUBNORM
 #error FLT_HAS_SUBNORM not defined
 #endif
@@ -55,7 +55,7 @@
 #error DECIMAL_DIG not defined
 #endif
 
-#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES)
+#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES) && 0
 #ifndef FLT_DECIMAL_DIG
 #error FLT_DECIMAL_DIG not defined
 #endif
@@ -165,7 +165,7 @@
 #error LDBL_MIN not defined
 #endif
 
-#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES)
+#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES) && 0
 #ifndef FLT_TRUE_MIN
 #error FLT_TRUE_MIN not defined
 #endif
Index: libcxx/test/std/language.support/support.limits/c.limits/cfloat.pass.cpp
===================================================================
--- libcxx/test/std/language.support/support.limits/c.limits/cfloat.pass.cpp
+++ libcxx/test/std/language.support/support.limits/c.limits/cfloat.pass.cpp
@@ -25,7 +25,7 @@
 #error FLT_RADIX not defined
 #endif
 
-#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES)
+#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES) && 0
 #ifndef FLT_HAS_SUBNORM
 #error FLT_HAS_SUBNORM not defined
 #endif
@@ -55,7 +55,7 @@
 #error DECIMAL_DIG not defined
 #endif
 
-#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES)
+#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES) && 0
 #ifndef FLT_DECIMAL_DIG
 #error FLT_DECIMAL_DIG not defined
 #endif
@@ -165,7 +165,7 @@
 #error LDBL_MIN not defined
 #endif
 
-#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES)
+#if TEST_STD_VER > 14 && defined(TEST_HAS_C11_FEATURES) && 0
 #ifndef FLT_TRUE_MIN
 #error FLT_TRUE_MIN not defined
 #endif