powerpc/aix atomic operations

[Hans-Peter Nilsson]

On Fri, 22 Apr 2005, Geoffrey Keating wrote:
>
> This patch does three things:
>
> - Works around the AIX assembler, which doesn't have local labels;

For the record I'd like to mention that there's an asm output
format "%=" to get a insn-unique counter, intended for use to
form local labels.  (You didn't mention why it wasn't used, so
someone may think there's no such support.)

brgds, H-P