re PR libstdc++/56841 (ld: Unsatisfied symbol "__atomic_exchange_8" in file /test/gnu/gcc/objdir/prev-hppa64-hp-hpux11.11/libstdc++-v3/src/.libs/libstdc++.a[eh_terminate.o])

	PR libstdc++/56841
	* libsupc++/eh_ptr.cc (rethrow_exception): Use get_unexpected() and
	get_terminate() accessors.
	* libsupc++/eh_throw.cc (__cxa_throw): Likewise.
	* libsupc++/eh_terminate.cc: Use mutex when atomic builtins not
	available.
	* libsupc++/new_handler.cc: Likewise.

From-SVN: r197512