* libsupc++/eh_alloc.cc: Ensure that required macros are

	* libsupc++/eh_alloc.cc: Ensure that required macros are
	defined before including gthr.h.  Ensure that we get the
	version of gthr.h for which we know how to provide a
	configuration.
	* libsupc++/eh_globals.cc: Likewise.  And, bring the threading
	code path into line with the current EH model.  Use std, where
	appropriate.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@42999 138bc75d-0d04-0410-961f-82ee72b054a4