new alias sets from the backend

[Jeffrey A Law]

  In message < 199809210251.TAA17652@smtp.earthlink.net >you write:
  > But, varargs macros do such tricky things that I recently turned off
  > the use of alias sets completely in varargs functions.  There should
  > be some information in the mail archives around the time of the patch
  > explaining the situation, I think.  If not, Jeff and I should be able
  > to dig it out of our combined mail files.
Right.  varargs/stdargs by their nature tend to create aliased memory
accesses which C claims can't/shouldn't happen.

Consider the register flush and the loads via va_arg.

jeff