[PyTorch] Fix string copy in WARN path for both interpreters (#54076)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/54076
If we don't constrain ourselves to use `torch::jit::pop`, we can avoid copying a string or moving IValues around.
ghstack-source-id: 124040891
Test Plan:
existing tests
spot-checked regular interpreter assembly; seems better
Reviewed By: dhruvbird, walterddr
Differential Revision: D27087204
fbshipit-source-id: 7cf355dbcec31409bdb37afa09d7df85cf2a7e4b
