Issue #11870: Skip test_threading.test_2_join_in_forked_process() on platforms with known OS bugs
Issue #11870: Skip test_threading.test_2_join_in_forked_process() on platforms
with known OS bugs

Share the list of platforms with known OS bugs with other tests. Patch written
by Charles-François Natali.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator