[libc++][atomic_ref] Fix cxx03 CI build

Author: dalg24

libcxx/include/__atomic/atomic_sync.h

@@ -12,13 +12,16 @@
 #include <__atomic/contention_t.h>
 #include <__atomic/cxx_atomic_impl.h>
 #include <__atomic/memory_order.h>
+#include <__atomic/to_gcc_order.h>
 #include <__availability>
 #include <__chrono/duration.h>
 #include <__config>
 #include <__memory/addressof.h>
 #include <__thread/poll_with_backoff.h>
 #include <__threading_support>
 #include <__type_traits/decay.h>
+#include <__type_traits/enable_if.h>
+#include <__type_traits/remove_cv.h>
 #include <cstring>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
@@ -35,8 +38,8 @@ struct __is_cxx_atomic_impl<__cxx_atomic_impl<_Tp> > : true_type {};
 
 template <class _Tp>
 _LIBCPP_HIDE_FROM_ABI __enable_if_t<!__is_cxx_atomic_impl<__remove_cv_t<_Tp> >::value, _Tp>
-__cxx_atomic_load(_Tp* __ptr, memory_order __order) noexcept {
-  alignas(_Tp) unsigned char __mem[sizeof(_Tp)];
+__cxx_atomic_load(_Tp* __ptr, memory_order __order) _NOEXCEPT {
+  _ALIGNAS_TYPE(_Tp) unsigned char __mem[sizeof(_Tp)];
   auto* __ret = reinterpret_cast<_Tp*>(__mem);
   __atomic_load(__ptr, __ret, __to_gcc_order(__order));
   return *__ret;

libcxx/include/module.modulemap.in

@@ -1096,7 +1096,10 @@ module std_private_atomic_atomic_flag         [system] {
 module std_private_atomic_atomic_init         [system] { header "__atomic/atomic_init.h" }
 module std_private_atomic_atomic_lock_free    [system] { header "__atomic/atomic_lock_free.h" }
 module std_private_atomic_atomic_ref          [system] { header "__atomic/atomic_ref.h" }
-module std_private_atomic_atomic_sync         [system] { header "__atomic/atomic_sync.h" }
+module std_private_atomic_atomic_sync         [system] {
+  header "__atomic/atomic_sync.h"
+  export std_private_atomic_to_gcc_order
+}
 module std_private_atomic_check_memory_order  [system] { header "__atomic/check_memory_order.h" }
 module std_private_atomic_contention_t        [system] { header "__atomic/contention_t.h" }
 module std_private_atomic_cxx_atomic_impl     [system] { header "__atomic/cxx_atomic_impl.h" }