[PATCH] resubmitted for review to fix modulo scheduling. COMMITTED

[David Edelsohn]

Kenneth Zadeck writes:

> It apparently suffers from several problems:
> reload scews it up (what a shocker!), it relies on patterns that only
> occur on the ppc, and the instructions are expanded on other platforms
> too late to get a good schedule.

	The modulo scheduling pass relies on the presence of doloop
patterns to recognize loops after many optimization passes have been
applied.  Eventually this should rely on Tree-SSA loop discovery.

	The doloop patterns are not limited to ppc.  Please do not
inaccurately parrot comments from IRC chat.

Thanks, David