[llvm] [AMDGPU][SIInsertWaitcnts][NFC] Introduce Counter class (PR #190271)

[Sameer Sahasrabuddhe via llvm-commits]

ssahasra wrote:

> Regarding this particular patch, do you have any specific changes in mind ?

Yes.

1. Complete the design document.
2. Provide more PRs (not just commits) showing how this "temporary" change will be fixed.

I am not actually convinced by the need for making this small change right now, but I am willing to move on simply because it is taking too much energy. But this intermediate fix by itself is not okay.

https://github.com/llvm/llvm-project/pull/190271