PR libstdc++/51135

    PR libstdc++/51135
        * libsupc++/unwind-cxx.h (__cxa_exception): Mark
        exceptionDestructor by _GLIBCXX_CDTOR_CALLABI.
        * libsupc++/eh_throw.cc (__cxa_throw): Mark destructor
        function argument by _GLIBCXX_CDTOR_CALLABI.
        * libsupc++/cxxabi.h (__cxa_throw): Likewise.
        (_GLIBCXX_CDTOR_CALLABI): Add empty default
        definition.
        * config/os/mingw32-w64/os_defines.h (_GLIBCXX_CDTOR_CALLABI): Define
        for IA-32 target as __thiscall.
        * config/os/mingw32/os_defines.h (_GLIBCXX_CDTOR_CALLABI): Likewise.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@182410 138bc75d-0d04-0410-961f-82ee72b054a4