Increase coverage of global loads in optimized code

src/hydrogen.h

Index: src/hydrogen.h
===================================================================
--- src/hydrogen.h	(revision 7468)
+++ src/hydrogen.h	(working copy)
@@ -453,6 +453,9 @@
   // the instruction as value.
   virtual void ReturnInstruction(HInstruction* instr, int ast_id) = 0;
 
+  void set_for_typeof(bool for_typeof) { for_typeof_ = for_typeof; }
+  bool is_for_typeof() { return for_typeof_; }
+
  protected:
   AstContext(HGraphBuilder* owner, Expression::Context kind);
   virtual ~AstContext();
@@ -469,6 +472,7 @@
   HGraphBuilder* owner_;
   Expression::Context kind_;
   AstContext* outer_;
+  bool for_typeof_;
 };
 
 
@@ -735,6 +739,7 @@
   void Bind(Variable* var, HValue* value) { environment()->Bind(var, value); }
 
   void VisitForValue(Expression* expr);
+  void VisitForTypeOf(Expression* expr);
   void VisitForEffect(Expression* expr);
   void VisitForControl(Expression* expr,
                        HBasicBlock* true_block,
@@ -770,9 +775,13 @@
   HBasicBlock* CreateLoopHeaderBlock();
 
   // Helpers for flow graph construction.
-  void LookupGlobalPropertyCell(Variable* var,
-                                LookupResult* lookup,
-                                bool is_store);
+  enum GlobalPropertyAccess {
+    kUseCell,
+    kUseGeneric
+  };
+  GlobalPropertyAccess LookupGlobalProperty(Variable* var,
+                                            LookupResult* lookup,
+                                            bool is_store);
 
   bool TryArgumentsAccess(Property* expr);
   bool TryCallApply(Call* expr);