ppc regression

[David Edelsohn]

	I originally was considering a splitter that was all RTL, letting
the compiler figure out the most efficient way to add four to the address,
but I can place the C code in the define_insn for the time being.  I would
not think that I would need all of the refers_to_regno_p() stuff if I were
using a splitter as the compiler would allocate registers appropriately
given its other uses.  No?

David