[llvm] [CodeGen] Use RegisterClassInfo for remaining allocation-order users (PR #216510)

[Nikhil Kotikalapudi via llvm-commits]

nkotikal wrote:

> LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-gcc-ubuntu` running on `sie-linux-worker3` while building `llvm` at step 6 "test-build-unified-tree-check-all".
> 
> Full details are available at: https://lab.llvm.org/buildbot/#/builders/174/builds/40839
> 
> Here is the relevant piece of the build log for the reference

This doesn't seem to be relevant to my PR? Wonder if it's a transient fail because I was the only one pinged on blamelist

https://github.com/llvm/llvm-project/pull/216510