[llvm] [InstCombine] Fold `(X & C1) | C2` into `X & (C1 | C2)` iff `(X & C2) == C2` (PR #76470)

[Yingwei Zheng via llvm-commits]

dtcxzyw wrote:

> Does this have compile-time impact?

Compile-time impact: http://llvm-compile-time-tracker.com/compare.php?from=38c9390b59c4d2b9181614d6a909887497d3692f&to=b96af27a97818b41a127113f4d4313aa704b2469&stat=instructions:u

|stage1-O3|stage1-ReleaseThinLTO| stage1-ReleaseLTO-g| stage1-O0-g|stage2-O3 |stage2-O0-g| stage2-clang|
|--|--|--|--|--|--|--|
|+0.01% |-0.00% |-0.01%| +0.03%|-0.02% |+0.01% |-0.00%|


https://github.com/llvm/llvm-project/pull/76470