Fix TSAN issue wrt assertions in the optimizing compiler thread.

src/hydrogen-environment-liveness.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 37 matching lines @@
   explicit HEnvironmentLivenessAnalysisPhase(HGraph* graph);
 
   void Run();
 
  private:
   void ZapEnvironmentSlot(int index, HSimulate* simulate);
   void ZapEnvironmentSlotsInSuccessors(HBasicBlock* block, BitVector* live);
   void ZapEnvironmentSlotsForInstruction(HEnvironmentMarker* marker);
   void UpdateLivenessAtBlockEnd(HBasicBlock* block, BitVector* live);
   void UpdateLivenessAtInstruction(HInstruction* instr, BitVector* live);
+#ifdef DEBUG
+  bool VerifyClosures(Handle<JSFunction> a, Handle<JSFunction> b);
+#endif
 
   int block_count_;
 
   // Largest number of local variables in any environment in the graph
   // (including inlined environments).
   int maximum_environment_size_;
 
   // Per-block data. All these lists are indexed by block_id.
   ZoneList<BitVector*> live_at_block_start_;
   ZoneList<HSimulate*> first_simulate_;
@@ skipping 11 matching lines @@
   HSimulate* last_simulate_;
   BitVector went_live_since_last_simulate_;
 
   DISALLOW_COPY_AND_ASSIGN(HEnvironmentLivenessAnalysisPhase);
 };
 
 
 } }  // namespace v8::internal
 
 #endif /* V8_HYDROGEN_ENVIRONMENT_LIVENESS_H_ */