[llvm] [AMDGPU] Enhance verification of amdgcn.cs.chain intrinsic (PR #128162)

[Matt Arsenault via llvm-commits]

arsenm wrote:

Right, we would need to fix the definition of callbr to permit intrinsics instead of only asm. We have several intrinsics which should naturally be terminators, but are not simply due to predating callbr and callbr starting out limited to asm 

https://github.com/llvm/llvm-project/pull/128162