[package] fix mangling issues with TorchScript (#54915)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/54915
TorchScript and torch.package have different mangling schemes. To avoid
them interfering with each other, we should undo the torch.package
mangling before processing anything with TorchScript (since TS
independently makes sure that no names collide).
Test Plan: Imported from OSS
Reviewed By: SplitInfinity
Differential Revision: D27410472
Pulled By: suo
fbshipit-source-id: d1cc013c532d9abb7fb9615122bc465ded4785bb
