[llvm] [CodeGen] Precompute untyped getMinimalPhysRegClass (PR #193438)

[Sander de Smalen via llvm-commits]

https://github.com/sdesmalen-arm commented:

Few minor nits, otherwise LGTM.

As a general comment, it would be nice if this could also be made to work for other value types (e.g. for AArch64 the number of register classes it would have to traverse if the type is not MVT::other, would always be <=2). But for other targets that might need some form of compressing the map.

https://github.com/llvm/llvm-project/pull/193438