Implement simple fast-path code for functions containing this property stores and global variables.

src/data-flow.h

Index: src/data-flow.h
diff --git a/src/data-flow.h b/src/data-flow.h
index e1f2200df8b93b6328740daf50eb825138422be0..ac8350318832f57593ab72382644b36d38865b5e 100644
--- a/src/data-flow.h
+++ b/src/data-flow.h
@@ -38,10 +38,12 @@ namespace internal {
 // their evaluation order (post-order left-to-right traversal).
 class AstLabeler: public AstVisitor {
  public:
-  AstLabeler() : next_number_(0) {}
+  AstLabeler() : next_number_(0), has_this_properties_(false) {}
 
   void Label(FunctionLiteral* fun);
 
+  bool has_this_properties() { return has_this_properties_; }
+
  private:
   void VisitDeclarations(ZoneList<Declaration*>* decls);
   void VisitStatements(ZoneList<Statement*>* stmts);
@@ -54,6 +56,8 @@ class AstLabeler: public AstVisitor {
   // Traversal number for labelling AST nodes.
   int next_number_;
 
+  bool has_this_properties_;
+
   DISALLOW_COPY_AND_ASSIGN(AstLabeler);
 };