[PATCH] Remove atomic_compare_and_exchange_bool_rel.

[Adhemerval Zanella]

On 14/06/2016 10:35, Torvald Riegel wrote:
> Removing this operation and the matching (unused) catomic_ operation
> seemed to be easier than fixing powerpc's definition of it, only for it
> to be removed anyway in the future.  There were just three call sites of
> it.
> 
> Tested on x86_64-linux.  Lei Xu, could you test on Power?
> 

LGTM and I have checked on powerpc64le (power8) and aarch64.  I think we
just need a confirmation that it works on e6500 from Lei Xu.