RS6000 Changes to support WindISS

[David Edelsohn]

>>>>> Mark Mitchell writes:

Mark> If you put that file in your libc -- or if it were in libgcc -- it
Mark> wouldn't need to be linked in explicitly, and then you could get by
Mark> with the usual FreeBSD spec.  I don't know why it's not in libgcc.

	It's not in libgcc because it always needs to be linked statically
or the call will trample registers the subroutine is trying to save and
restore.

	Alan Modra has a change in binutils to generate the subroutine
automatically when linking.  I do not know what sort of prerequisite we
can place on binutils when upgrading GCC.

	Another solution is to make the crtsavres.o file a spec that can
be dynamically included based on %{mwindiss}.

	By the way, Mark, you introduced a typo: the file is crtsavres.o
not crtsaveres.o -- no "e" in "sav".

David