[Ada] Fix to 64-bit atomic operation failures on ppc-linux

[Richard Henderson]

On 07/17/2012 04:57 AM, Andrew MacLeod wrote:
> What is the nature of the atomic failures using the
> __atomic_compare_exchange built-in?   Does it have anything to do
> with the expected value being returned by pointer?

It's a rue.  He never was using __atomic_compare_exchange;
the "Atomic_*" was simply the Ada symbol name.


r~