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

[Krzysztof Drewniak via llvm-commits]

krzysz00 wrote:

> 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?

Module flags?

(Which, well, relaxed-oob-mode - or its inverse - should also be)

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