jemalloc on ppc32: Missing implementation for 32-bit atomic operations

[Ingvar Hagelund]

* Jason wrote, some time back in April that
> > gcc added intrinsics for atomic operations sometime in the 4.x
> > series (4.4.x certainly has them), which jemalloc tries to use
> > (...)
> > so chances are that you are using a newer compiler on the ppc64
> > system than on the 32-bit system.

As announced elsewhere, I did a build of jemalloc-2.2.5 for rhel5
(epel5) today. This is still a problem on rhel5/ppc.

Default gcc for rhel5 is 4.1.2 (with som redhat specific patches, of course)

Ingvar