[libc++] Move the definition of std::new_handler out of new.cpp

[ldionne]

Summary

This reduces the difference between libc++'s new.cpp and libc++abi's
stdlib_new_delete.cpp files, which are essentially copies of each other.

libcxx/src/CMakeLists.txt

set(LIBCXX_SOURCES
   include/ryu/ryu.h
   include/to_chars_floating_point.h
   legacy_pointer_safety.cpp
   memory.cpp
   memory_resource.cpp
   mutex.cpp
   mutex_destructor.cpp
   new.cpp
+  new_handler.cpp
   optional.cpp
   random_shuffle.cpp
   ryu/d2fixed.cpp
   ryu/d2s.cpp
   ryu/f2s.cpp
   shared_mutex.cpp
   stdexcept.cpp
   string.cpp
   support/runtime/exception_fallback.ipp
   support/runtime/exception_glibcxx.ipp
   support/runtime/exception_libcxxabi.ipp
   support/runtime/exception_libcxxrt.ipp
   support/runtime/exception_msvc.ipp
   support/runtime/exception_pointer_cxxabi.ipp
   support/runtime/exception_pointer_glibcxx.ipp
   support/runtime/exception_pointer_msvc.ipp
   support/runtime/exception_pointer_unimplemented.ipp
-  support/runtime/new_handler_fallback.ipp
   support/runtime/stdexcept_default.ipp
   support/runtime/stdexcept_vcruntime.ipp
   system_error.cpp
   thread.cpp
   typeinfo.cpp
   valarray.cpp
   variant.cpp
   vector.cpp

libcxx/src/new.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include <__memory/aligned_alloc.h>
 #include <new>
 #include <stdlib.h>
 
-#include "include/atomic_support.h"
-
-#if defined(_LIBCPP_ABI_MICROSOFT)
-#   if !defined(_LIBCPP_ABI_VCRUNTIME)
-#       include "support/runtime/new_handler_fallback.ipp"
-#   endif
-#elif defined(LIBCXX_BUILDING_LIBCXXABI)
-#   include <cxxabi.h>
-#elif defined(LIBCXXRT)
-#   include <cxxabi.h>
-#   include "support/runtime/new_handler_fallback.ipp"
-#elif defined(__GLIBCXX__)
-    // nothing to do
-#else
-#   include "support/runtime/new_handler_fallback.ipp"
-#endif
-
 namespace std
 {
 
 #ifndef __GLIBCXX__
 const nothrow_t nothrow{};
 #endif
 
 #ifndef LIBSTDCXX

libcxx/src/new_handler.cpp

-// -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-namespace std {
+#include <new>
+
+#include "include/atomic_support.h"
+
+#if defined(_LIBCPP_ABI_MICROSOFT)
+#   if !defined(_LIBCPP_ABI_VCRUNTIME)
+#       define _LIBPCPP_DEFINE_NEW_HANDLER
+#   endif
+#elif defined(LIBCXX_BUILDING_LIBCXXABI)
+    // nothing to do, we use the one from libc++abi
+#elif defined(LIBCXXRT)
+#   define _LIBPCPP_DEFINE_NEW_HANDLER
+#elif defined(__GLIBCXX__)
+    // nothing to do, we use the one from libstdc++/libsupc++
+#else
+#   define _LIBPCPP_DEFINE_NEW_HANDLER
+#endif
+
+#if defined(_LIBPCPP_DEFINE_NEW_HANDLER)
+
+namespace std { // purposefully not versioned
 
 static constinit std::new_handler __new_handler = nullptr;
 
 new_handler
 set_new_handler(new_handler handler) noexcept
 {
     return __libcpp_atomic_exchange(&__new_handler, handler);
 }
 
 new_handler
 get_new_handler() noexcept
 {
     return __libcpp_atomic_load(&__new_handler);
 }
 
 } // namespace std
+
+#endif // _LIBPCPP_DEFINE_NEW_HANDLER

libcxx/utils/data/ignore_format.txt

 libcxx/src/ios.cpp
 libcxx/src/iostream.cpp
 libcxx/src/legacy_debug_handler.cpp
 libcxx/src/locale.cpp
 libcxx/src/memory.cpp
 libcxx/src/mutex.cpp
 libcxx/src/mutex_destructor.cpp
 libcxx/src/new.cpp
+libcxx/src/new_handler.cpp
 libcxx/src/optional.cpp
 libcxx/src/random.cpp
 libcxx/src/random_shuffle.cpp
 libcxx/src/regex.cpp
 libcxx/src/shared_mutex.cpp
 libcxx/src/stdexcept.cpp
 libcxx/src/std_stream.h
 libcxx/src/string.cpp
 libcxx/src/strstream.cpp
 libcxx/src/support/ibm/mbsnrtowcs.cpp
 libcxx/src/support/ibm/wcsnrtombs.cpp
 libcxx/src/support/ibm/xlocale_zos.cpp
 libcxx/src/support/runtime/exception_fallback.ipp
 libcxx/src/support/runtime/exception_glibcxx.ipp
 libcxx/src/support/runtime/exception_libcxxabi.ipp
 libcxx/src/support/runtime/exception_libcxxrt.ipp
 libcxx/src/support/runtime/exception_msvc.ipp
 libcxx/src/support/runtime/exception_pointer_cxxabi.ipp
 libcxx/src/support/runtime/exception_pointer_glibcxx.ipp
 libcxx/src/support/runtime/exception_pointer_msvc.ipp
 libcxx/src/support/runtime/exception_pointer_unimplemented.ipp
-libcxx/src/support/runtime/new_handler_fallback.ipp
 libcxx/src/support/runtime/stdexcept_default.ipp
 libcxx/src/support/runtime/stdexcept_vcruntime.ipp
 libcxx/src/support/win32/locale_win32.cpp
 libcxx/src/support/win32/support.cpp
 libcxx/src/support/win32/thread_win32.cpp
 libcxx/src/system_error.cpp
 libcxx/src/thread.cpp
 libcxx/src/typeinfo.cpp
 libcxx/src/valarray.cpp
 libcxx/src/variant.cpp
 libcxx/src/vector.cpp
 libcxx/src/verbose_abort.cpp