Simplify recursive script compilation flow. (#31019)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/31019
No more `recurisve_script`, just direct calls to `create_script_module`.
This reduces the number of pathways through the frontend, and the
uniformity is useful for a future PR.
Test Plan: Imported from OSS
Differential Revision: D18904113
Pulled By: suo
fbshipit-source-id: 7de061dfef0cbdfc9376408fc6c1167b81803f01
