[jit] allow submodule methods inference rule be different (#43872)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/43872
This PR allows the recursive scripting to have a separate
submodule_stubs_fn to create its submodule with specific user provided
rules.
Fixes https://github.com/pytorch/pytorch/issues/43729
Test Plan: Imported from OSS
Reviewed By: suo
Differential Revision: D23430176
Pulled By: wanchaol
fbshipit-source-id: 20530d7891ac3345b36f1ed813dc9c650b28d27a
