[llvm] [CodeGen] Add MachineRegisterClassInfo analysis pass (PR #120690)

[Pengcheng Wang via llvm-commits]

wangpc-pp wrote:

> RegisterClassInfo already has a pass-like interface (`runOnMachineFunction`) - could we just change it into a proper pass instead of adding MachineRegisterClassInfo as a wrapper?

Thanks for your advice! I thought about the same thing, but it is not possible since RegisterClassInfo is also an utility class. Please see previous discussion: https://github.com/llvm/llvm-project/pull/118787#issuecomment-2550564056.

https://github.com/llvm/llvm-project/pull/120690