[turbofan] Tentative fix for ControlEquivalence crasher.

src/compiler/control-equivalence.h

 // Copyright 2014 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_CONTROL_EQUIVALENCE_H_
 #define V8_COMPILER_CONTROL_EQUIVALENCE_H_
 
 #include "src/base/compiler-specific.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/node.h"
@@ skipping 106 matching lines @@
   //   / \          to D have been visited, we pop N and call VisitPost(N).
   //
   // This will yield a true spanning tree (without cross or forward edges) and
   // also discover proper back edges in both directions.
   void RunUndirectedDFS(Node* exit);
 
   void DetermineParticipationEnqueue(ZoneQueue<Node*>& queue, Node* node);
   void DetermineParticipation(Node* exit);
 
  private:
-  NodeData* GetData(Node* node) { return &node_data_[node->id()]; }
+  NodeData* GetData(Node* node) {
+    size_t const index = node->id();
+    if (index >= node_data_.size()) node_data_.resize(index + 1, EmptyData());
+    return &node_data_[index];
+  }
   int NewClassNumber() { return class_number_++; }
   int NewDFSNumber() { return dfs_number_++; }
 
   // Template used to initialize per-node data.
   NodeData EmptyData() {
     return {kInvalidClass, 0, false, false, false, BracketList(zone_)};
   }
 
   // Accessors for the DFS number stored within the per-node data.
   size_t GetNumber(Node* node) { return GetData(node)->dfs_number; }
@@ skipping 27 matching lines @@
   int dfs_number_;    // Generates new DFS pre-order numbers on demand.
   int class_number_;  // Generates new equivalence class numbers on demand.
   Data node_data_;    // Per-node data stored as a side-table.
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_CONTROL_EQUIVALENCE_H_