bpo-45020: Default to using frozen modules only on non-debug builds.

[ericsnowcurrently]

This should give us the default we normally want, "on", without disrupting contributors too much. This should be a good-enough place to start. We can adjust the heuristic (e.g. PGO or running-in-source-tree) later if needed.

https://bugs.python.org/issue45020

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @ericsnowcurrently for commit 60b8694 🤖

If you want to schedule another build, you need to add the ":hammer: test-with-buildbots" label again.

[ericsnowcurrently]

3 buildbots failed, all non-debug, all with the same failure in idlelib.idle_test.test_help_about.LiveDialogTest.test_printer_buttons (name='license'):

• https://buildbot.python.org/all/#/builders/449/builds/183
• https://buildbot.python.org/all/#/builders/465/builds/196
• https://buildbot.python.org/all/#/builders/344/builds/196

This matches the failures on the Windows checks (which are also non-debug).

[gvanrossum]

Looks like something is finding a data file (some license) by using __file__?

[ericsnowcurrently]

I prefer gh-28940, so I'm tabling this for now.