[JIT][Symbolic Shape Analysis] expose op shape functions (#68748)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/68748
Test Plan: Imported from OSS
Reviewed By: eellison
Differential Revision: D32598605
Pulled By: makslevental
fbshipit-source-id: c97a06cd0fe143a6ea14db65fc5d3f76abdff312
