libport: Fix build on PowerPC

[André Hentschel]

Am 27.05.2015 um 11:18 schrieb Grazvydas Ignotas:
> On Tue, May 26, 2015 at 11:16 PM, André Hentschel <nerv at dawncrow.de> wrote:
>> It was broken by recent commits
>> ---
>>  libs/port/interlocked.c | 15 +++++++++++++++
> 
> Maybe we could just drop all this powerpc specific code, especially
> considering missing cmpxchg64 implementation (better use mutex
> fallback there) and that some other platforms (ARM/ARM64) don't have
> any of this anyway and just use the fallbacks.

A better idea is to implement cmpxchg64 in assembler, i already talked with slackner about that.
it'll take i while as i have a lot of work to do in wine alone, and i also have a lot of other things to do...