[llvm] [AMDGPU] Add function attribute to disable TBUFFER combine (PR #156454)

[Piotr Sobczak via llvm-commits]

piotrAMD wrote:

> Also, should this be a function-level or module-level property? It feels module-level, in that your entire program either does or doesn't want these semantics?

Yes, this is more like module-level property. But function attribute is a standard way to pass this kind of information from the front-end to the backend. Is there a better option?

https://github.com/llvm/llvm-project/pull/156454