[FX][WIP] Mutable Graph APIs (#45227)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/45227
Test Plan: Imported from OSS
Reviewed By: zdevito
Differential Revision: D23880730
Pulled By: jamesr66a
fbshipit-source-id: eb4e8c14d7f6b1deb1ddd6cf38a360413a1705ed
