[turbofan] Introduce DeadValue and DeadEffect operators.

src/compiler/verifier.cc

Index: src/compiler/verifier.cc
diff --git a/src/compiler/verifier.cc b/src/compiler/verifier.cc
index e678f4e6a5e955e31bf12586e20b0de067c04069..bf039e386179395144f9783c77cfde730b9e1bf3 100644
--- a/src/compiler/verifier.cc
+++ b/src/compiler/verifier.cc
@@ -192,7 +192,9 @@ void Verifier::Visitor::Check(Node* node) {
       // Type is empty.
       CheckNotTyped(node);
       break;
-    case IrOpcode::kDead:
+    case IrOpcode::kDeadValue:
+    case IrOpcode::kDeadEffect:
+    case IrOpcode::kDeadControl:
       // Dead is never connected to the graph.
       // TODO(mstarzinger): Make the GraphReducer immediately perform control
       // reduction in case control is killed. This will prevent {Dead} from