bpo-40275: test.support imports subprocess lazily by vstinner · Pull Request #20471 · python/cpython

@vstinner

test.support module now imports the platform and subprocess modules
lazily to reduce the number of modules imported by
"import test.support".

With this change, the threading module is no longer imported
indirectly by "import test.support".

Use sys.version rather than platform.machine() to detect the Windows
ARM32 buildbot.