os_defines.h (_GLIBCXX_LLP64): Define if llp64 abi is used.

	* config/os/mingw32/os_defines.h (_GLIBCXX_LLP64): Define if llp64
	abi is used.
	* config/os/mingw32-w64/os_defines.h: Likewise.
	* libsupc++/cxxabi.h (__base_class_type_info): Adjust
	type of __offset_flags for llp64.
	* libsupc++/eh_alloc.cc (EMERGENCY_OBJ_SIZE): Define proper
	for llp64 abi.
	(EMERGENCY_OBJ_COUNT): Likewise.
	(bitmask_type): Likewise.
	* libsupc++/hash_bytes.cc (_Hash_bytes): Handle llp64.

From-SVN: r194658