libcxx: Stop using private MSVC macros in the exception implementation.

[pcc]

Summary

Inline the provided "fallback" definitions (which seem to always be
taken) that expand to __cdecl into users. The fallback definitions
for the *CRTIMP* macros were wrong in the case where the library is
being linked statically, so define our own macro as a replacement.

[smeenai]

LGTM.

libcxx/include/__config

namespace std {
   }
 }
 
 #define _LIBCPP_HAS_NO_ASAN
 
 #endif // _LIBCPP_COMPILER_[CLANG|GCC|MSVC|IBM]
 
 #if defined(_LIBCPP_OBJECT_FORMAT_COFF)
+#ifdef _DLL
+# define _LIBCPP_CRT_FUNC __declspec(dllimport)
+#else
+# define _LIBCPP_CRT_FUNC
+#endif
+
 #if defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
 # define _LIBCPP_DLL_VIS
 # define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
 # define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
 # define _LIBCPP_OVERRIDABLE_FUNC_VIS
 #elif defined(_LIBCPP_BUILDING_LIBRARY)
 # define _LIBCPP_DLL_VIS __declspec(dllexport)
 # define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS

libcxx/src/support/runtime/exception_msvc.ipp

 
 #ifndef _LIBCPP_ABI_MICROSOFT
 #error this header can only be used when targeting the MSVC ABI
 #endif
 
 #include <stdio.h>
 #include <stdlib.h>
 
-#if !defined(_ACRTIMP)
-#define _ACRTIMP __declspec(dllimport)
-#endif
-
-#if !defined(_VCRTIMP)
-#define _VCRTIMP __declspec(dllimport)
-#endif
-
-#if !defined(__CRTDECL)
-#define __CRTDECL __cdecl
-#endif
-
 extern "C" {
-typedef void (__CRTDECL* terminate_handler)();
-_ACRTIMP terminate_handler __cdecl set_terminate(
+typedef void (__cdecl* terminate_handler)();
+_LIBCPP_CRT_FUNC terminate_handler __cdecl set_terminate(
     terminate_handler _NewTerminateHandler) throw();
-_ACRTIMP terminate_handler __cdecl _get_terminate();
+_LIBCPP_CRT_FUNC terminate_handler __cdecl _get_terminate();
 
-typedef void (__CRTDECL* unexpected_handler)();
-_VCRTIMP unexpected_handler __cdecl set_unexpected(
+typedef void (__cdecl* unexpected_handler)();
+_LIBCPP_CRT_FUNC unexpected_handler __cdecl set_unexpected(
     unexpected_handler _NewUnexpectedHandler) throw();
-_VCRTIMP unexpected_handler __cdecl _get_unexpected();
+_LIBCPP_CRT_FUNC unexpected_handler __cdecl _get_unexpected();
 
-_VCRTIMP int __cdecl __uncaught_exceptions();
+_LIBCPP_CRT_FUNC int __cdecl __uncaught_exceptions();
 }
 
 namespace std {
 
 unexpected_handler
 set_unexpected(unexpected_handler func) _NOEXCEPT {
   return ::set_unexpected(func);
 }

libcxx/src/support/runtime/exception_pointer_msvc.ipp

 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #include <stdio.h>
 #include <stdlib.h>
 
-#if !defined(_CRTIMP2_PURE)
-#define _CRTIMP2_PURE __declspec(dllimport)
-#endif
-
-#if !defined(__CLRCALL_PURE_OR_CDECL)
-#define __CLRCALL_PURE_OR_CDECL __cdecl
-#endif
-
-_CRTIMP2_PURE void __CLRCALL_PURE_OR_CDECL __ExceptionPtrCreate(void*);
-_CRTIMP2_PURE void __CLRCALL_PURE_OR_CDECL __ExceptionPtrDestroy(void*);
-_CRTIMP2_PURE void __CLRCALL_PURE_OR_CDECL __ExceptionPtrCopy(void*,
-                                                              const void*);
-_CRTIMP2_PURE void __CLRCALL_PURE_OR_CDECL
-__ExceptionPtrAssign(void*, const void*);
-_CRTIMP2_PURE bool __CLRCALL_PURE_OR_CDECL
-__ExceptionPtrCompare(const void*, const void*);
-_CRTIMP2_PURE bool __CLRCALL_PURE_OR_CDECL
-__ExceptionPtrToBool(const void*);
-_CRTIMP2_PURE void __CLRCALL_PURE_OR_CDECL __ExceptionPtrSwap(void*, void*);
-_CRTIMP2_PURE void __CLRCALL_PURE_OR_CDECL
-__ExceptionPtrCurrentException(void*);
-[[noreturn]] _CRTIMP2_PURE void __CLRCALL_PURE_OR_CDECL
-__ExceptionPtrRethrow(const void*);
-_CRTIMP2_PURE void __CLRCALL_PURE_OR_CDECL
+_LIBCPP_CRT_FUNC void __cdecl __ExceptionPtrCreate(void*);
+_LIBCPP_CRT_FUNC void __cdecl __ExceptionPtrDestroy(void*);
+_LIBCPP_CRT_FUNC void __cdecl __ExceptionPtrCopy(void*, const void*);
+_LIBCPP_CRT_FUNC void __cdecl __ExceptionPtrAssign(void*, const void*);
+_LIBCPP_CRT_FUNC bool __cdecl __ExceptionPtrCompare(const void*, const void*);
+_LIBCPP_CRT_FUNC bool __cdecl __ExceptionPtrToBool(const void*);
+_LIBCPP_CRT_FUNC void __cdecl __ExceptionPtrSwap(void*, void*);
+_LIBCPP_CRT_FUNC void __cdecl __ExceptionPtrCurrentException(void*);
+[[noreturn]] _LIBCPP_CRT_FUNC void __cdecl __ExceptionPtrRethrow(const void*);
+_LIBCPP_CRT_FUNC void __cdecl
 __ExceptionPtrCopyException(void*, const void*, const void*);
 
 namespace std {
 
 exception_ptr::exception_ptr() _NOEXCEPT { __ExceptionPtrCreate(this); }
 exception_ptr::exception_ptr(nullptr_t) _NOEXCEPT { __ExceptionPtrCreate(this); }
 
 exception_ptr::exception_ptr(const exception_ptr& __other) _NOEXCEPT {