[PATCH] powerpc: emulate power5 popcntb instruction

[Paul Mackerras]

Segher Boessenkool writes:

> Like I asked before -- should we run this emulation on 32-bit
> machines at all?  The instruction only exists in the 64-bit
> architecture after all.

It could be argued either way, but on the whole I would prefer to
minimize the number of things which could cause a 32-bit program that
runs quite happily on a 64-bit CPU to fail on a 32-bit CPU...

Paul.