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

[Matt Arsenault via llvm-commits]

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@@ -6367,6 +6367,8 @@ void Verifier::visitIntrinsicCall(Intrinsic::ID ID, CallBase &Call) {
           "SGPR arguments must have the `inreg` attribute", &Call);
     Check(!Call.paramHasAttr(3, Attribute::InReg),
           "VGPR arguments must not have the `inreg` attribute", &Call);
+    Check(dyn_cast_or_null<UnreachableInst>(Call.getNextNode()),
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arsenm wrote:

isa_or_null?

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