[patch] fix prefetch-3 on x86_64 darwin

[Paolo Bonzini]

Eric Christopher wrote:
> So, the testcase fails because the processor listed isn't acceptable for 
> 64-bit architectures, this change fixes it. There are other possible 
> changes, but this is where i'd probably go if it were my testcase. On a 
> side note, shouldn't this be in the gcc.target/i386 directory?

I don't think so, as it tests a generic optimization in such a way that 
it can only run under the i386 (actually I think it might pass on many 
other systems, but nobody bothered to check).  gcc.target/i386 is for 
tests of the i386 backend's features, as far as I understand.

Paolo