alias analysis refactor take 2 (#17594)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/17594
The original version of this broke things because a concurrent change raced with it in CI.
Reviewed By: ezyang
Differential Revision: D14266663
fbshipit-source-id: e8ac5dfcb7349b4f2c425d9f0eabbfc964314063
