[PyTorch] Merge CoinflipTLS into RecordFunctionTLS (#49359)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/49359
This should be both slightly more efficient (1 less TLS guard
check in at::shouldRunRecordFunction) and definitely more correct
(CoinflipTLS is now saved whenever RecordFunctionTLS is saved), fixing
a bad merge that left RecordFunctionTLS::tries_left dead.
ghstack-source-id: 118624402
Test Plan: Review, CI
Reviewed By: hlu1
Differential Revision: D25542799
fbshipit-source-id: 310f9fd157101f659cea13c331b2a0ee6db2db88
