[llvm] [CodeGen][SDAG] Remove Combiner WorklistMap (PR #92900)

[Jay Foad via llvm-commits]

https://github.com/jayfoad commented:

> This brings a substantial performance improvement, see [here (compile-time-tracker)](http://llvm-compile-time-tracker.com/compare.php?from=9d70975c7a72f3fa58d2d63090b92886dbf8a32b&to=13eff8c73d11595da9c01a0bb6580fea698aa3c9&stat=instructions:u).

Nice!

https://github.com/llvm/llvm-project/pull/92900