pytorch

83287a6f - [pytorch] change codegen dispatch key from string to enum (#51115)

[pytorch] change codegen dispatch key from string to enum (#51115) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/51115 Add enum type for dispatch key. Prepare to implement the DispatchTable computation logic in python for static dispatch. Verified byte-for-byte compatibility of the codegen output. Test Plan: Imported from OSS Reviewed By: bhosmer Differential Revision: D26077430 Pulled By: ljk53 fbshipit-source-id: 86e74f3eb32266f31622a2ff6350b91668c8ff42