[turbolizer] Visualize also the dead nodes.

src/compiler/all-nodes.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_ALL_NODES_H_
 #define V8_COMPILER_ALL_NODES_H_
 
 #include "src/compiler/node.h"
 #include "src/zone-containers.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 // A helper utility that traverses the graph and gathers all nodes reachable
 // from end.
 class AllNodes {
  public:
-  // Constructor. Traverses the graph and builds the {live} sets.
-  AllNodes(Zone* local_zone, const Graph* graph);
+  // Constructor. Traverses the graph and builds the {reachable} sets. When
+  // {only_inputs} is true, find the nodes reachable through input edges;
+  // these are all live nodes.
+  AllNodes(Zone* local_zone, const Graph* graph, bool only_inputs = true);
 
   bool IsLive(Node* node) {
+    CHECK(only_inputs_);
+    return IsReachable(node);
+  }
+
+  bool IsReachable(Node* node) {
     if (!node) return false;
     size_t id = node->id();
-    return id < is_live.size() && is_live[id];
+    return id < is_reachable_.size() && is_reachable_[id];
   }
 
-  NodeVector live;  // Nodes reachable from end.
+  NodeVector reachable;  // Nodes reachable from end.
 
  private:
-  BoolVector is_live;
+  BoolVector is_reachable_;
+  const bool only_inputs_;
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_ALL_NODES_H_