Revert D23223281: Add Enum TorchScript serialization and deserialization support
Test Plan: revert-hammer
Differential Revision:
D23223281 (https://github.com/pytorch/pytorch/commit/f269fb83c104cb8e4106171fd70aac6cb0f930cf)
Original commit changeset: 716d1866b777
fbshipit-source-id: da1ad8387b7d7aad9ff69e1ebeb5cd0b9394c2df
