Add __code__ to types.MethodType

[Avasam]

I have no idea if this is even correct. But here's the PR that made me add this: mhammond/pywin32#2385 and here's a short repro:

import types

class A:
    def test(self): ...

print(type(A().test) is types.MethodType)
print(A().test.__code__)
A().test.__code__ = None

results in:

True
<code object test at 0x00000236894BB660, file "c:\Users\Avasam\Desktop\import types.py", line 4>
Traceback (most recent call last):
  File "c:\Users\Avasam\Desktop\import types.py", line 8, in <module>
    A().test.__code__ = None
AttributeError: 'method' object has no attribute '__code__'

[github-actions]

According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉

[srittau]

This is a weird one, but the change look kinda correct to me.