[llvm] [AMDGPU] Support arbitrary types in amdgcn.dead (PR #134841)

[Matt Arsenault via llvm-commits]

================
@@ -9116,6 +9121,12 @@ SDValue SITargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op,
   case Intrinsic::amdgcn_mov_dpp8:
   case Intrinsic::amdgcn_update_dpp:
     return lowerLaneOp(*this, Op.getNode(), DAG);
+  case Intrinsic::amdgcn_dead: {
+    SmallVector<SDValue, 8> Undefs;
+    for (unsigned I = 0, E = Op.getNode()->getNumValues(); I != E; ++I)
+      Undefs.push_back(DAG.getUNDEF(Op.getNode()->getValueType(I)));
+    return DAG.getMergeValues(Undefs, SDLoc(Op));
----------------
arsenm wrote:

Poison? 

https://github.com/llvm/llvm-project/pull/134841