new syscall stub support for ia64 libc

[David Mosberger]

>>>>> On Mon, 8 Dec 2003 17:08:44 +0100, Jakub Jelinek <jakub@redhat.com> said:

  Jakub> I've briefly looked at .unwabi and will fix it in
  Jakub> unwind-ia64.c as well as other issues which I'll come over.

If you really want to keep the old unwinder alive, could you at least
put it in a separate (shared) library called libunwind.so?  I'm
concerned about version-mismatches that can occur when libgcc_eh.a
gets linked into a program and then libgcc_s.so gets loaded as well.
The version conflict arises because of potential differences in the
_Unwind_Context structure.  If libgcc_eh.a doesn't implement any part
of the _Unwind_*() routines, such version conflicts should be much
less likely.  This is the approach I'm now pursuing with libunwind: it
implements all the _Unwind_*() routines needed by GCC so no part of
that interface gets implemented in libgcc_eh.a anymore.  libunwind has
been updated already, but I haven't submitted a GCC patch yet, because
I can't get through to the CVS server (due to the savannah break-in, I
assume).

	--david