Deeply rework WeakIdKeyDictionary (#90825)
In the prior patch, I just YOLOed a mutable mapping implementation.
Many edge cases were not handled correctly. In this PR, I just
copy paste the WeakKeyDictionary from CPython and the hacked it up
to use WeakIdRef instead of weakref.ref. You can see each line
I changed with the comment CHANGED; there aren't many.
Being exactly API compatible with WeakKeyDictionary means I can also
rob all of the tests from CPython, which I also did for
test/test_weak.py
How to review? You could either try taking the delta from CPython
(recommended), or review everything from scratch (not recommended).
Can post diff representing delta on request.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/90825
Approved by: https://github.com/albanD
