strengthen protection against REG_EQUIV/EQUAL on !REG set

[Olivier Hainque]

Hello Richard,

On Apr 25, 2012, at 00:06 , Richard Sandiford wrote:
> STRICT_LOW_PART is OK too.

 Ah, right.

> Would be nice to use a single function that knows about the extra
> contraints here.  Maybe something like the attached?
> 
> I'm deliberately requiring the SET to the first rtx in the PARALLEL.

 Looks cleaner indeed. Do you want me to test ?

 Thanks a lot for your feedback.

 Olivier