r255887 has broken the tests on OS X for the dwarf version of that test. Can you please either fix it to work on OS X, or revert the change? I’m not interested in disabling that test on OS X since it covers important functionality.
Now that the test rerun support is in, I’ll be able to turn on the test runner portion of the OS X buildbot soon so this would have been more obvious.
You can also mark https://llvm.org/bugs/show_bug.cgi?id=25872 that I filed yesterday with whichever you do.