[llvm] [PredicateInfo] Cache ssa.copy declarations (NFC) (PR #145020)

[Yingwei Zheng via llvm-commits]

dtcxzyw wrote:

https://llvm-compile-time-tracker.com/compare.php?from=5dbfe2e1ea9d50ff259a66ddb8f085c5ec560132&to=db03308056d8c6236bdf322246e5327cb6cfaf16&stat=instructions:u

https://github.com/llvm/llvm-project/pull/145020