It reverts r331378 as it caused test failures
ThreadSanitizer-x86_64 :: Darwin/gcd-groups-destructor.mm
ThreadSanitizer-x86_64 :: Darwin/libcxx-shared-ptr-stress.mm
ThreadSanitizer-x86_64 :: Darwin/xpc-race.mm
Only clang part of the change is reverted, libc++ part remains as is because it
emits error less aggressively.
llvm-svn: 331392
# include_next <stdatomic.h>
#else
-#if !defined(__ALLOW_STDC_ATOMICS_IN_CXX__) && defined(__cplusplus)
-#error "<stdatomic.h> is incompatible with the C++ standard library; define __ALLOW_STDC_ATOMICS_IN_CXX__ to proceed."
-#endif
-
#include <stddef.h>
#include <stdint.h>
+++ /dev/null
-// RUN: %clang_cc1 %s -verify
-// RUN: %clang_cc1 -D__ALLOW_STDC_ATOMICS_IN_CXX__ %s -verify
-
-#include <stdatomic.h>
-
-#ifndef __ALLOW_STDC_ATOMICS_IN_CXX__
-// expected-error@stdatomic.h:* {{<stdatomic.h> is incompatible with the C++ standard library}}
-#else
-// expected-no-diagnostics
-#endif