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

[Krzysztof Drewniak via llvm-commits]

krzysz00 wrote:

I'd also like to take the opportunity to flag that relaxed-buffer-oob-mode should either be a module-level or a function-level property ... and should actually have its default flipped (to strict-oob-mode on a module, for example - or maybe that'd be an HSA-specific thing)

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