Reload patch to improve 386 code

[Jeffrey A Law]

  In message < 199809080059.BAA01948@phal.cygnus.co.uk >you write:
  > > > Then again inheritance happens just before we start emitting the
  > > > reload insns themselves, so maybe it doesn't conflict with your code.
  > > 
  > > It really shouldn't. Inheritance only looks at the insns that reload is
  > > already done with, and the one currently being processed.  For those
  > > which reload has completed, the register life information calculated by
  > > my patch is never referenced again, so the inheritance code can do
  > > whatever it wants to them.
  > 
  > You'll have to add some code to tell the inheritance code when a reload
  > register becomes unavailable where it becomes used by a pseudo.
Yup.  But that shouldn't be too difficult.  In forget_old_reloads_1
we look at reg_renumber for the pseudo and invalidate things as needed.

jeff