[PATCH] PowerPC VLE port

[David Edelsohn]

Jim,

This version of the VLE support patch is an improvement, although I
still am troubled by the number of changes to rs6000.md.

And can you suggest any way to re-factor rs6000_rtx_costs()?

Andrew suggested placing all of the patterns in vle.md independently
and without my prompting.  VLE really is more of a separate
architecture that happens to share some similarities and mnemonics
with PowerPC, not a variant of PowerPC.

I agree with Andrew that the cleanup portions of the patch should be
sent separately.

I also am continuing to work with Mike Meissner on the target flags
patch, which will affect this patch.

Thanks, David