[JIT] Propagate type sharing setting to submodule compilation (#44226)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/44226
**Summary**
At present, the `share_types` argument to `create_script_module` is used
to decide whether to reuse a previously created type for a top-level
module that has not yet been compiled. However, that setting does not apply
to the compilation of submodules of the top-level module; types are
still reused if possible.
This commit modifies `create_script_module` so that the `share_types`
flag is honoured during submodule compilation as well.
**Test Plan**
This commit adds a unit test to `TestTypeSharing` that checks that
submodule types are not shared or reused when `share_types` is set to
`False`.
**Fixes**
This commit fixes #43605.
Test Plan: Imported from OSS
Reviewed By: eellison
Differential Revision: D23602371
Pulled By: SplitInfinity
fbshipit-source-id: b909b8b6abbe3b4cb9be8319ac263ade90e83bd3
