Message 256250 - Python tracker

A type-based check runs into problems with 0.0 vs -0.0. For example, on Python 2.7.11:

>>> x, y = lambda: 0.0, lambda: -0.0
>>> y()
0.0

I wasn't able to reproduce the -0.0 problem with Python 3.4 on Ideone; y.__code__.co_consts seems to have an unused 0.0 in it on 3.4. I don't have access to Python 3.5, so I don't know what the situation is like on that version.