Enable more patterns for powerpc64

[Alan Modra]

On Wed, Jul 24, 2002 at 09:58:29PM -0400, David Edelsohn wrote:
> 	Replace "T" and "S" constraints with "i" when the predicate will do.
> 
> I thought that this was going to change to "n", not "i".

We've been using "i", but I'm quite happy with "n" too.  In fact,
even an "X" should work, as the predicate does all the checking
necessary.  The main idea in not using "S" or "T" is to avoid
calling the predicate again, as that is what rs6000.h
EXTRA_CONSTRAINT does.

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre