Add AliasDb API For Changing Aliasing (#31501)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/31501
We have a number of places in our code base where we should be checking if it's safe to change the alias relationship between two sets of values. This PR adds an api to Alias Db to consolidate the logic, and refactors Constant Pooling and `CSE` to use the new api. Next steps: add api usage in peephole.cpp where applicable.
Happy to bikeshed `AliasDb::safeToChangeAliasingRelationship`. Previously I suggested `AliasDb::safeToIntroduceAliasing`, however that's not quite accurate, because this API also handles when it is unsafe to remove aliasing.
Alternate suggestions: `safeToChangeAliasing`, `validToChangeAliasing`, `validToChangeAliasingRelationship`
Related: https://github.com/pytorch/pytorch/issues/28360
Test Plan: Imported from OSS
Differential Revision: D19254413
Pulled By: eellison
fbshipit-source-id: 17f7f52ad2d1526d303132767cbbb32f8189ae15
