OSX Test Failures

[Matthew Pickering]

Occasionally a do a full validate on OSX, there are usually some tests
which fail but not on other systems. I usually don't report these
failures as there are always some and they are usually do to do with
parts of the compiler I don't know anything about.

However, on https://phabricator.haskell.org/D2485 Richard (Fung) and
Ben were discussing these failures which I have also seen so it seems
I would have wasted less time if I had reported these somewhere.

What is the expectation for OSX? Should the test suite be entirely
clean? Should I create issues when some of the tests get broken?

Matt