[PATCH] Simplify rest_of_compilation logic

[law@redhat.com]

 In message <20020613185339.GC4837@catalonia>, Matt Kraai writes:
 > > Err, umm, I bootstrapped the PPC yesterday.  Can you give more details ab=
 > out
 > > what's failing?
 > 
 > I reported it to GNATS, see Problem Report 7020.
Ah.  Two things.  One it's ppc-linux, I bootstrapped aix.  Two it requires
my patch from this morning to trigger the failure.

It's a pretty interesting issue -- enough that we may have to back out the
last round of patches to force sharing of more hard reg objects.

Anyway, I'm testing a patch for the ppc now, but I worry that other targets
may run into similar problems.
jeff