longlong.h macros for common PPC

[Jeffrey A Law]

  In message < m3r9hgh1va.fsf@localhost.localnet >you write:
  > Geoff Keating <geoffk@ozemail.com.au> writes:
  > 
  > > If I remember correctly, there simply isn't a 32x32->64 multiply that
  > > is common to both the power and ppc instruction sets, so you're stuck.
  > > The only multiply instruction available is a 32x32->32.
  > 
  > Well, but then in longlong.h the definitions should be surrended by
  > something like
  > 
  > 	#ifndef COM
  > 	#endif
  > 
  > in case the common ISA is selected.
  > 
  > > If you allow _both_ power and ppc, you want to use the power version
  > > with the MQ register, because reading the MQ is faster than a
  > > multiply-high instruction.
  > 
  > Yeah, but POWER is going away.  Almost all machines IBM is shipping
  > nowadays are PowerPC based, esp all 64bit enabled versions.  So
  > PowerPC should become the only option.
POWER may not be of interest to you, but GCC must continue to support it.

jeff