conditions when regrtest is run with its -j option.

for extension modules on Windows.

Thanks to Eric Snow for helping with imp.load_module() (previous
commit) which led to the removal of a bunch of C code.

Issue #14589: Update certificate chain for sha256.tbs-internet.com, fixing a test failure in test_ssl.

Issue #14589: Update certificate chain for sha256.tbs-internet.com, fixing a test failure in test_ssl.

__loader__.

Since import now sets __loader__ on all modules it creates and
imp.reload() already relied on the attribute for modules that import
didn't create, the only potential compatibility issue is if people
were deleting the attribute on modules and expecting imp.reload() to
continue to work.

rewriting functionality in pure Python.

To start, imp.new_module() has been rewritten in pure Python, put into
importlib (privately) and then publicly exposed in imp.

of sys.modules when possible.

This is being done for two reasons. One is to gain a little bit of
performance by skipping an unnecessary dict lookup in sys.modules. But
the other (and main) reason is to be a little bit more clear in how
things should work from the perspective of import's interactions with
loaders. Otherwise loaders can easily forget to return the module even
though PEP 302 explicitly states they are expected to return the module
they loaded.

found in sys.modules.