Reloading the warnings module duplicates filters in warnings.filters. Fixing
the issue is tricky. It was decided to simply remove the check from Python 3.5,
since the bug only impacts Python unit tests, not real applications.
The check is kept in Python 3.6 and newer.
regrtest -W hides output if a test pass, but also when env changed and so the
env changed warning is hidden. So it's hard to debug. With this change, stderr
is now always displayed when a test doesn't pass.
* Rename libregrtest.main_in_temp_cwd() to libregrtest.main()
* Add regrtest.main_in_temp_cwd() alias to libregrtest.main()
* Move old main_in_temp_cwd() code into libregrtest.Regrtest.main()
* Update multiple scripts to call libregrtest.main()
Since PGO building doesn't care about test failures, silence them when
running the test suite for performance reasons. Initial patch by
Alecsandru Patrascu of Intel.
Start to split regrtest.py into smaller parts with the creation of
Lib/test/libregrtest/cmdline.py: code to handle the command line, especially
parsing command line arguments. This part of the code is tested by
test_regrtest.
