branch analysis

[asottile]

I'm creating this mostly as a duplicate target

pyflakes currently does not do any branch analysis and as such can't really know when things are conditionally defined / undefined / dead code / etc.

doing accurate branch analysis is a hard problem and often requires some amount of dynamic analysis so it is unlikely pyflakes will ever actually implement this

there are better alternatives which attempt to do this such as type checkers (mypy, pyright) and to some extent pylint