[llvm] [AMDGPU] Require explicit immediate offsets for SGPR+IMM SMEM instructions. (PR #79131)

[Ivan Kosarev via llvm-commits]

kosarev wrote:

> Do I get it right, there are no user visible changes?

There are no intended functional changes, yes. By making immediate offsets mandatory we just ensure that where they are not specified, the SGPR-only variants of instructions will be used.

https://github.com/llvm/llvm-project/pull/79131