[InstCombine] Canonicalize `switch(C-X)` to `switch(X)` (#77051)

This patch canonicalizes `switch(C-X)` to `switch(X)`.

Compile-time impact:
http://llvm-compile-time-tracker.com/compare.php?from=7954c57124b495fbdc73674d71f2e366e4afe522&to=31a9adff1e633f0f3c423fb8487fc15d17e171f2&stat=instructions:u

|stage1-O3|stage1-ReleaseThinLTO|stage1-ReleaseLTO-g|stage1-O0-g|stage2-O3|stage2-O0-g|stage2-clang|
|--|--|--|--|--|--|--|
|-0.01%|+0.02%|+0.02%|+0.05%|-0.07%|-0.02%|-0.02%|