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

[Patrick Simmons via llvm-commits]

linuxrocks123 wrote:

@arsenm taking some backend issues to do first since this is just a compilation time optimization.  I still plan to get to this, but I am not prioritizing it highly so someone else can take it if they want.  If they do, I've brought this pass up-to-date in https://github.com/llvm/llvm-project/pull/164877 so that would be the one to work on.  This PR should be closed now (but I do not have rights to do that).

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