[llvm] AMDGPU/MC: Fix emitting absolute expressions (PR #136789)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> Any suggestions as to how? In the downstream case, this is triggered by a new MCResourceInfo::ResourceInfoKind which can be placed into an instruction operand. It's possible I missed something, but in main these enums only seem to be used in connection to the kernel descriptor. 

So emit a kernel descriptor? 

https://github.com/llvm/llvm-project/pull/136789