Nvfuser faster fallback
Follow up to #76505
Addressing https://github.com/pytorch/pytorch/pull/76505#discussion_r861260818 to further improve fallback perf during compilation failure. This allows us to reuse fallback instead re-constructing new code every time.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/76604
Approved by: https://github.com/davidberard98
