[PATCH] fix PR target/54407

[Mike Stump]

On Oct 16, 2012, at 6:03 AM, Jack Howarth <howarth@bromo.med.uc.edu> wrote:
>  The attached patch eliminates the execution failures in 30_threads/condition_variable/54185.cc
> on darwin by limiting the test to darwin11 or later. The test is disabled on darwin10 and earlier
> which has broken pthread support.

I'm not a big fan of just hiding the bug; why not just xfail it of darwin10 and darwin[5-9]?