[libc++abi] Revert temporary workaround to unblock Chrome

This reverts commit 372f7dd, which is not needed by Chrome anymore.

Author: ldionne

libcxxabi/src/cxa_exception_storage.cpp

@@ -12,12 +12,7 @@
 
 #include "cxa_exception.h"
 
-// TODO: Temporary workaround, see https://github.com/llvm/llvm-project/pull/79654#issuecomment-1919397302
-#if __has_include(<__thread/support.h>)
-#  include <__thread/support.h>
-#else
-#  include <__threading_support>
-#endif
+#include <__thread/support.h>
 
 #if defined(_LIBCXXABI_HAS_NO_THREADS)
 

libcxxabi/src/cxa_guard_impl.h

@@ -55,13 +55,7 @@
 #  endif
 #endif
 
-// TODO: Temporary workaround, see https://github.com/llvm/llvm-project/pull/79654#issuecomment-1919397302
-#if __has_include(<__thread/support.h>)
-#  include <__thread/support.h>
-#else
-#  include <__threading_support>
-#endif
-
+#include <__thread/support.h>
 #include <cstdint>
 #include <cstring>
 #include <limits.h>

libcxxabi/src/cxa_thread_atexit.cpp

@@ -8,12 +8,7 @@
 
 #include "abort_message.h"
 #include "cxxabi.h"
-// TODO: Temporary workaround, see https://github.com/llvm/llvm-project/pull/79654#issuecomment-1919397302
-#if __has_include(<__thread/support.h>)
-#  include <__thread/support.h>
-#else
-#  include <__threading_support>
-#endif
+#include <__thread/support.h>
 #ifndef _LIBCXXABI_HAS_NO_THREADS
 #if defined(__ELF__) && defined(_LIBCXXABI_LINK_PTHREAD_LIB)
 #pragma comment(lib, "pthread")

libcxxabi/src/fallback_malloc.cpp

@@ -9,12 +9,7 @@
 #include "fallback_malloc.h"
 #include "abort_message.h"
 
-// TODO: Temporary workaround, see https://github.com/llvm/llvm-project/pull/79654#issuecomment-1919397302
-#if __has_include(<__thread/support.h>)
-#  include <__thread/support.h>
-#else
-#  include <__threading_support>
-#endif
+#include <__thread/support.h>
 #ifndef _LIBCXXABI_HAS_NO_THREADS
 #if defined(__ELF__) && defined(_LIBCXXABI_LINK_PTHREAD_LIB)
 #pragma comment(lib, "pthread")

libcxxabi/test/test_fallback_malloc.pass.cpp

@@ -11,12 +11,7 @@
 #include <cassert>
 #include <inttypes.h>
 
-// TODO: Temporary workaround, see https://github.com/llvm/llvm-project/pull/79654#issuecomment-1919397302
-#if __has_include(<__thread/support.h>)
-#  include <__thread/support.h>
-#else
-#  include <__threading_support>
-#endif
+#include <__thread/support.h>
 
 // UNSUPPORTED: c++03
 // UNSUPPORTED: modules-build && no-threads