Revert "Redesign Straight-Line Strength Reduction (SLSR) (#162930)" (#169546)
This reverts commit f67409c3ec7cd45c55656c8159bc42b3918f1116.
cc @fiigii
Including us, several separate groups are experiencing regressions with
this change. This is the smallest reproducer pasted by @akuegel :
https://github.com/llvm/llvm-project/pull/162930#issuecomment-3574307330