Disallow assignment to None, False, True and __debug__

[JukkaL]

The front end lets programs assign to None, False, True and __debug__, even though this is disallowed in Python. Disallow these assignments, similar to Python.

[Varriount]

This would be fixed by modifying the semantic analyzer, semanal.py , right? Specifically the assignment analysis function?

[JukkaL]

Yes, that's correct.

And sorry for the late reply. I had a nasty cold last week.

[gvanrossum]

This will be fixed with #1353.