[llvm] [AMDGPU] Add an asm directive to track code_object_version (PR #76267)

[Fangrui Song via llvm-commits]

MaskRay wrote:

> Requesting review from @MaskRay as someone outside AMD to look, in particular because of the generic change needed in `MCAssembler`.

Thanks. I've left some comments.

https://github.com/llvm/llvm-project/pull/76267