[llvm] [InstCombine] Canonicalize `extractvalue + select` (PR #84686)

[Yingwei Zheng via llvm-commits]

dtcxzyw wrote:

> @dtcxzyw If it is viable from a compile-time perspective, we could change the fold to use InstSimplify instead of ConstantFolding...

Compile-time impact: https://llvm-compile-time-tracker.com/compare.php?from=3ec1f25f3cf9346590892397ec9ddd859397d363&to=0370e494c190b02a4548f85d480c437ddafd44d8&stat=instructions:u

https://github.com/llvm/llvm-project/pull/84686