[llvm] [AMDGPU] Relax SOPK immediate signed/unsigned check (PR #77015)

[Stanislav Mekhanoshin via llvm-commits]

rampitec wrote:

> The MIR verifier has no bearing on the assembler support. This check is for our own sanity, so we should just be better about marking instructions with sopkIsZext

The problem with the check is that it triggers on user code, not something we are creating inside the compiler. A user code just calls setreg intrinsic and fall into the problem. What is worse it only happens with debug build. I could change the operand to be unsigned, although it is not what is written in SP3, but it will break sources which are now using negative constants to w/a this problem.

https://github.com/llvm/llvm-project/pull/77015