PR c++/28145

    PR c++/28145
        * libsupc++/cxxabi.h (__forced_unwind, __foreign_exception):
        New classes.
        * libsupc++/eh_exception.cc: Define their destructors.
        * config/abi/pre/gnu.ver: Export their type_infos.
        * config/abi/pre/gnu-versioned-namespace.ver: Likewise.
        * libsupc++/eh_personality.cc: A handler for abi::__forced_unwind
        matches a forced unwind, and a handler for abi::__foreign_exception
        matches a foreign exception.

        * include/bits/istream.tcc: Rethrow forced unwind.
        * include/bits/ostream.tcc: Likewise.
        * include/bits/ostream_insert.h: Likewise.
        * include/bits/basic_string.tcc (operator>>, getline): Likewise.
        * include/bits/fstream.tcc (basic_filebuf::close): Likewise.
        * include/ext/vstring.cc (operator>>, getline): Likewise.
        * src/istream.cc: Likewise.
        * src/compatibility.cc (basic_istream::ignore): Likewise.
        * include/std/bitset (operator>>): Likewise.
        * include/std/fstream (basic_filebuf::close): Remove throw() spec.
        * libsupc++/cxxabi-internal.h: Split out from...
        * libsupc++/cxxabi.h: ...here.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@124517 138bc75d-0d04-0410-961f-82ee72b054a4