[PyTorch] Reduce heap allocations in OperatorName::setNamespaceIfNotSet (#64673)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/64673
We are now guaranteed to allocate at most one time in this function.
ghstack-source-id: 137786392
Test Plan: Previous diff adds test coverage for this function.
Reviewed By: dhruvbird
Differential Revision: D30813014
fbshipit-source-id: 17d844a1cc8c30574afcc6b0b41b219e62c0b723
