Yeah, it was only when we went to add "test.pkg_helper" (so that test_runpy and test_pkgutil could share it) that we put the brakes on and decided to stop making a bad situation worse and do something different.

There are probably some other helpers we could spin out over time (like those for creating test servers). It becomes much easier to do that kind of refactoring once there's an obvious place to put them without bloating the test/support.py to crazy levels.