Add boolean flag to HChange and LNumberUntagD to not convert undefined to NaN.

src/hydrogen.h

 // Copyright 2011 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 198 matching lines @@
   Zone* zone() { return isolate_->zone(); }
 
   const ZoneList<HBasicBlock*>* blocks() const { return &blocks_; }
   const ZoneList<HPhi*>* phi_list() const { return phi_list_; }
   HBasicBlock* entry_block() const { return entry_block_; }
   HEnvironment* start_environment() const { return start_environment_; }
 
   void InitializeInferredTypes();
   void InsertTypeConversions();
   void InsertRepresentationChanges();
+  void MarkDeoptimizeOnUndefined();
   void ComputeMinusZeroChecks();
   bool ProcessArgumentsObject();
   void EliminateRedundantPhis();
   void EliminateUnreachablePhis();
   void Canonicalize();
   void OrderBlocks();
   void AssignDominators();
   void ReplaceCheckedValues();
 
   // Returns false if there are phi-uses of the arguments-object
@@ skipping 44 matching lines @@
                  HBasicBlock* loop_header);
   void PostorderLoopBlocks(HLoopInformation* loop,
                            BitVector* visited,
                            ZoneList<HBasicBlock*>* order,
                            HBasicBlock* loop_header);
   HConstant* GetConstant(SetOncePointer<HConstant>* pointer,
                          Object* value);
 
   void InsertTypeConversions(HInstruction* instr);
   void PropagateMinusZeroChecks(HValue* value, BitVector* visited);
+  void RecursivelyMarkPhiDeoptimizeOnUndefined(HPhi* phi);
   void InsertRepresentationChangeForUse(HValue* value,
                                         HValue* use_value,
                                         int use_index,
                                         Representation to);
   void InsertRepresentationChangesForValue(HValue* value);
   void InferTypes(ZoneList<HValue*>* worklist);
   void InitializeInferredTypes(int from_inclusive, int to_inclusive);
   void CheckForBackEdge(HBasicBlock* block, HBasicBlock* successor);
 
   Isolate* isolate_;
@@ skipping 898 matching lines @@
   const char* filename_;
   HeapStringAllocator string_allocator_;
   StringStream trace_;
   int indent_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_H_