[turbofan] Proper dead code elimination as regular reducer.

src/compiler/js-graph.cc

Index: src/compiler/js-graph.cc
diff --git a/src/compiler/js-graph.cc b/src/compiler/js-graph.cc
index 10e20a1bd5f772e0377541f9b13ee5098392f5d8..b247f8a19f534f6b9cf70fb76178ae1813541f59 100644
--- a/src/compiler/js-graph.cc
+++ b/src/compiler/js-graph.cc
@@ -203,13 +203,8 @@ Node* JSGraph::EmptyFrameState() {
 }
 
 
-Node* JSGraph::DeadValue() {
-  return CACHED(kDeadValue, graph()->NewNode(common()->DeadValue()));
-}
-
-
-Node* JSGraph::DeadControl() {
-  return CACHED(kDeadControl, graph()->NewNode(common()->DeadControl()));
+Node* JSGraph::Dead() {
+  return CACHED(kDead, graph()->NewNode(common()->Dead()));
 }