[PyTorch] add fastToString for infer_schema (#64823)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/64823
We seem to spend noticable time in vfprintf for this, and the number of arguments is almost always small enough to do this in just a few instructions.
ghstack-source-id: 138623354
Test Plan: Profile schema parsing, saw less time in vfprintf
Reviewed By: ezyang, dhruvbird
Differential Revision: D30860716
fbshipit-source-id: 09ef085cd6f93dc1eaa78790dde918ac60e67450
