run-tests: introduce PYTHON3 boolean constant (
issue4668)
This will avoid open-coding lots of version_info checks later in the
file.
run-tests: drop subprocess _cleanup monkeypatch
This was working around a defect in subprocess in Python 2.5, which we
no longer need to worry about.
run-tests: drop wifexited polyfill
os.WIFEXITED exists as of python 2.6 for me, so we no longer need this
polyfill.
test-import: update for no-execbit platforms with
1ef96a3b8b89
cleanup: use __builtins__.any instead of util.any
any() is available in all Python versions we support now.