[llvm] [CodeGen] Renumber slot indexes before register allocation (PR #66334)

[Jay Foad via llvm-commits]

jayfoad wrote:

> My concerns is that it adds compile time and may trigger other renumbering down the line. The compile time impact is probably in the noise (@jayfoad have you double check?)

Yes, see earlier comment :)

> https://llvm-compile-time-tracker.com/ shows a geomean 0.00% change.

This was based on the "renumber-all-slotindexes" branch here: https://llvm-compile-time-tracker.com/?config=NewPM-O3&stat=instructions%3Au&remote=jayfoad

https://github.com/llvm/llvm-project/pull/66334