there's a bug open atm requesting we add biarch support to our x86/amd64
compilers [1]. i'd like to take this further and do it for all ppc systems
too (sparc has already done this). basically, this just affects the code that
gcc can generate. it does not affect the libraries it includes.

i haven't heard any feedback from peeps, so if no one has any reason not to do
this, i'll enable it prob this weekend.

the advantage is that it should obsolete the separate kgcc64 package for most
people. and i think it might help out with the multilib bootstrap issue: you
can't build multilib gcc without a multilib glibc, and can't build a multilib
glibc without a multilib gcc, but i think you should be able to build a
multilib glibc with a multiarch gcc, and then a multilib gcc after that.
-mike