[llvm] [RegAlloc] Sort CopyHint by IsCSR (PR #131046)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> @arsenm I'm having some trouble coming up with a test case that isn't an exact clone of one of the existing tests, even after running through llvm-reduce.

Which case is this? You were trying llvm-reduce on the MIR? I can try to see if my out of tree patches help reduce it any 

https://github.com/llvm/llvm-project/pull/131046