Allocate arguments object on-demand instead of at function entry....

src/scopes.h

 // Copyright 2006-2008 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 29 matching lines @@
  public:
   LocalsMap();
 
   // Dummy constructor.  This constructor doesn't set up the map
   // properly so don't use it unless you have a good reason.
   explicit LocalsMap(bool gotta_love_static_overloading);
 
   virtual ~LocalsMap();
 
   Variable* Declare(Scope* scope, Handle<String> name, Variable::Mode mode,
-                    bool is_valid_LHS, bool is_this);
+                    bool is_valid_LHS, Variable::Kind kind);
 
   Variable* Lookup(Handle<String> name);
 };
 
 
 // The dynamic scope part holds hash maps for the variables that will
 // be looked up dynamically from within eval and with scopes. The objects
 // are allocated on-demand from Scope::NonLocal to avoid wasting memory
 // and setup time for scopes that don't need them.
 class DynamicScopePart : public ZoneObject {
@@ skipping 313 matching lines @@
   virtual VariableProxy* NewUnresolved(Handle<String> name, bool inside_with) {
     return NULL;
   }
   virtual VariableProxy* NewTemporary(Handle<String> name)  { return NULL; }
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_SCOPES_H_