[llvm] [AMDGPU] Mark ASYNCMARK as meta instruction to fix hazard cycle miscounting (PR #189981)

[Ryan Mitchell via llvm-commits]

RyanRio wrote:

Seems messy, could we create another property like meta that (right now) asyncmark would have and that the hazard recognizer could skip?

https://github.com/llvm/llvm-project/pull/189981