[llvm] [AMDGPU] Make readonly noilas kernel arguments constant memory (PR #139629)

[Krzysztof Drewniak via llvm-commits]

krzysz00 wrote:

Closing per previous concern about correctness issues. However, what we probably should do is generalize https://github.com/llvm/llvm-project/blob/23a674d2ecc428a96d28c9772cc5178eaf763863/llvm/lib/Target/NVPTX/NVPTXTagInvariantLoads.cpp because we have the same behavior

https://github.com/llvm/llvm-project/pull/139629