using frame pointer + constant in reg_equiv_constant

[Jeffrey A Law]

  In message < 199812010156.RAA03440@rtl.cygnus.com >you write:
  > 	Maybe Jim will approve it.
  > 
  > Yes, I will, because the patch looks reasonable to me.  I don't see any of
  > the problems that you suspect might be there.  I am even more sure of this
  > now that I've debugged the x86 LEGITIMATE_CONSTANT_P problem you referred
  > to.
As I said, that was an *instance* of the problem.  I've been bitten by this
behavior in reload consistently for the last 6 years.   If you think it is
safe, go ahead and approve it.  Just be ready for problems.

jeff