[jit] `__copy__` for `RecursiveScriptModule` (#36830)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/36830
Test Plan:
build/bin/test_jit
Imported from OSS
Differential Revision: D21431012
fbshipit-source-id: 13a1bf9744ec95ea59622226c8d8a8d55ec3f0b0
