Changing the default 32-bit x86 arch for Fedora 12

[Bill Nottingham]

Gregory Maxwell (gmaxwell at gmail.com) said: 
> Is dropping hardware worth this instruction? I suggested some
> benchmarking and demonstrated that it's a very small improvement for
> Theora. I'm not sure if anyone got around to testing freetype,
> firefox, or any of the other couple CPU heavy desktop apps.
> 
> It would probably be most interesting to perform that test on the
> x86-only ATOM, since I can see CMOV being a bigger win on an in-order
> CPU.
> 
> (I can't personally protest: I think all the x86 stuff I have has CMOV).

Last time I profiled it (using the bits of openbench that actually worked),
i586 -> i686 was an improvement of 1% (Core2Duo) to 2% (Atom). Athlon64 was
essentially equal.

SPECCPU results showed similar. 

Bill