Allow registration of custom symbolics for prim namespace (#64460) (#66139)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/66139
[ONNX] Add prim::PythonOp check back in export.cpp (#64944)
Add prim::PythonOp check back in export.cpp
Test Plan: Imported from OSS
Reviewed By: malfet
Differential Revision: D31424102
fbshipit-source-id: 6d2eef767fab846ed79ea509e97b714072bac9f4
Co-authored-by: jiafatom <jiafa@microsoft.com>
