Add optimized compiler support for generic global loads....

src/hydrogen.h

Index: src/hydrogen.h
===================================================================
--- src/hydrogen.h	(revision 7145)
+++ src/hydrogen.h	(working copy)
@@ -445,6 +445,8 @@
   // the instruction as value.
   virtual void ReturnInstruction(HInstruction* instr, int ast_id) = 0;
 
+  virtual bool IsTypeof() { return false; }
+
  protected:
   AstContext(HGraphBuilder* owner, Expression::Context kind);
   virtual ~AstContext();
@@ -479,12 +481,17 @@
 class ValueContext: public AstContext {
  public:
   explicit ValueContext(HGraphBuilder* owner)
-      : AstContext(owner, Expression::kValue) {
+      : AstContext(owner, Expression::kValue), is_typeof_(false) {
   }
   virtual ~ValueContext();
 
   virtual void ReturnValue(HValue* value);
   virtual void ReturnInstruction(HInstruction* instr, int ast_id);
+  virtual bool IsTypeof() { return is_typeof_; }
+  void MarkAsTypeof() { is_typeof_ = true; }
+
+ private:
+  bool is_typeof_;
 };
 
 
@@ -727,6 +734,7 @@
   void Bind(Variable* var, HValue* value) { environment()->Bind(var, value); }
 
   void VisitForValue(Expression* expr);
+  void VisitForTypeofValue(Expression* expr);
   void VisitForEffect(Expression* expr);
   void VisitForControl(Expression* expr,
                        HBasicBlock* true_block,
@@ -762,7 +770,7 @@
   HBasicBlock* CreateLoopHeaderBlock();
 
   // Helpers for flow graph construction.
-  void LookupGlobalPropertyCell(Variable* var,
+  bool LookupGlobalPropertyCell(Variable* var,
                                 LookupResult* lookup,
                                 bool is_store);