[llvm] [CodeGen] Add code new pm code stubs for all backends (PR #78552)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm commented:

Not sure if it's a good idea to do every target at once until there's an effort to port that target's passes. If the interface changes again when bringing these up, it will just be a larger hassle to update all the implementations 

https://github.com/llvm/llvm-project/pull/78552