[llvm] AMDGPU: Replace copy-to-mov-imm folding logic with class compat checks (PR #154501)

[Aiden Grossman via llvm-commits]

boomanaiden154 wrote:

It broke the premerge bot as well https://lab.llvm.org/staging/#/builders/21/builds/1619.

It looks like a mid-air collision given this wasn't caught by the premerge checks. Those LLDB failures are also old.

https://github.com/llvm/llvm-project/pull/154501