[v3] enable threads tests for darwin

[Loren James Rittle]

> 2003-04-15  Andreas Tobler  <a.tobler@schweiz.ch>

>         * testsuite/thread/pthread1.cc: Enable for darwin test.
>         * testsuite/thread/pthread2.cc: Same.
>         * testsuite/thread/pthread3.cc: Same.
>         * testsuite/thread/pthread4.cc: Same.
>         * testsuite/thread/pthread5.cc: Same.
>         * testsuite/thread/pthread6.cc: Same.

Ack.  Permission to check into 3.3 and mainline.  Thanks for taking
the time to look at the threaded cases on your platform.

Regards,
Loren