First simplistic implementation of escape analysis.

src/hydrogen.h

 // Copyright 2012 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 212 matching lines @@
   bool Done() { return current_ >= predecessor_list_->length(); }
   HBasicBlock* Current() { return predecessor_list_->at(current_); }
   void Advance() { current_++; }
 
  private:
   const ZoneList<HBasicBlock*>* predecessor_list_;
   int current_;
 };
 
 
+class HInstructionIterator BASE_EMBEDDED {
+ public:
+  explicit HInstructionIterator(HBasicBlock* block)
+      : block_(block), instr_(block->first()) { }
+
+  bool Done() { return instr_ == block_->last(); }
+  HInstruction* Current() { return instr_; }
+  void Advance() { instr_ = instr_->next(); }
+
+ private:
+  HBasicBlock* block_;
+  HInstruction* instr_;
+};
+
+
 class HLoopInformation: public ZoneObject {
  public:
   HLoopInformation(HBasicBlock* loop_header, Zone* zone)
       : back_edges_(4, zone),
         loop_header_(loop_header),
         blocks_(8, zone),
         stack_check_(NULL) {
     blocks_.Add(loop_header, zone);
   }
   virtual ~HLoopInformation() {}
@@ skipping 1804 matching lines @@
   EmbeddedVector<char, 64> filename_;
   HeapStringAllocator string_allocator_;
   StringStream trace_;
   int indent_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_H_