[llvm] [RegisterCoalescer]: Try inflated RC for coalescing (PR #130870)

[Jeffrey Byrnes via llvm-commits]

jrbyrnes wrote:

> I'm actively working on avoiding using AGPRs until the actual allocation forces it. I was also wondering if instead we should just be using the AV_* classes for all values in the first place.

I think if we were to switch to AV_* we would need to coordinate a scheduler change as well (assuming the scheduler sees all these AV_*s and the switch is not done after) since the generic trackers don't handle AV_*s well. In general, the scheduler is able to do a better job if it knows which registers will be assigned to AGPR vs VGPR. 

https://github.com/llvm/llvm-project/pull/130870