Message 162335 - Python tracker

Stephen D'Aprano just asked on Python list how to get signatures of builtins, noting that calling inspect.getargspec on a Python-coded subclass of a builtin class raises an exception. So we need another testcase, verify the behavior, and probably add try-except around the inspect call. (Perhaps inspect.py should be revised to not leak an exception when given the advertised acceptible input, but that is another issue.)