Docstring of the file:

"""Run Python's standard test suite using importlib.__import__.

Tests known to fail because of assumptions that importlib (properly)
invalidates are automatically skipped if the entire test suite is run.
Otherwise all command-line options valid for test.regrtest are also valid for
this script.

"""

Since Python 3 now uses importlib by default for __import__, I think that the file became useless and can be removed.