[libgomp] Add Unix95 mutex support

[Andrew Pinski]

On Feb 16, 2006, at 2:51 AM, Jakub Jelinek wrote:
> No, because gthr-* headers implement an optional threading support,
> while in libgomp we want unconditional, so all the weak fn pointer
> comparisons etc. would just slow things down.

You can define GTHREAD_USE_WEAK to zero unconditionally when including
the file so the slow down is not there at all.

-- Pinski