[2.7] bpo-31160: Backport reap_children fixes from master to 2.7 by vstinner · Pull Request #3063

[2.7] bpo-31160: Backport reap_children fixes from master to 2.7 by vstinner · Pull Request #3063 · python/cpython

added 2 commits

Add a post_test_cleanup() function which currently only calls
support.reap_children().
(cherry picked from commit e3510d7)

TestRandomNameSequence.test_process_awareness() now calls
os.waitpid() to avoid leaking a zombie process.
(cherry picked from commit 6c8c294)