mv-python

@jacobtylerwalls unfortunately even after the fix (testing on main), there is a leak - consider following example: ```python from pylint.lint import Run from pylint.lint import pylinter while True: Run(["pylint/checkers/variables.py"], exit=False)...

Unfortunately running gc does not help: ```python from pylint.lint import Run from pylint.lint import pylinter import gc while True: Run(["pylint/checkers/variables.py"], exit=False) gc.collect() pylinter.MANAGER.clear_cache() ``` 

I think it is ready for review now.

> I'm still a little suspicious of the entries on types, I understand that and agree but unfortunately, I was not able to find better solution too. I would like...

> Can we try to go step by step? Allow the really simple and obvious `cdef const float x = 5.5` first, then continue from there? OK PR created, I...

Yes as I said, offloading C utility code is much more "low level" which can easily go wrong. I did not study C functions in deep so take my examples...

> I agree that we should start with the infrastructure implementation and the obvious/easy utility code sections, and then expand on them in separate refactoring PRs. I created such PR...

Maybe we can change the logic of the function to be more standard. E.g. this is the logic of pylint: https://pylint.pycqa.org/en/latest/faq.html#where-is-the-persistent-data-stored-to-compare-between-successive-runs

> I suspect that changes on with this PR. I'm not yet quite sure exactly how it should change but it's probably worth considering. Yes indeed this PR allows `None`...

> I think the easiest fix is to change `NoneNode.analyse_as_type` to: It seems to work. The only side-effect is that we are returning different error for following case: ```cython def...