Rename DispatchKey::UndefinedTensorId to Undefined (#32728)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/32728
It doesn't have much to do with tensors anymore.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Test Plan: Imported from OSS
Differential Revision: D19628093
Pulled By: ezyang
fbshipit-source-id: 4d57111cdf44ba347bec8a32bb5b4b47a83c1eaf
