Don't generate inline constructors if this.__proto__ is assigned....

src/parser.cc

 // 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 1567 matching lines @@
       Property* property = assignment->target()->AsProperty();
       return assignment->op() == Token::ASSIGN
              && property != NULL
              && property->obj()->AsVariableProxy() != NULL
              && property->obj()->AsVariableProxy()->is_this();
     }
     return false;
   }
 
   void HandleThisPropertyAssignment(Scope* scope, Assignment* assignment) {
-    // Check that the property assigned to is a named property.
+    // Check that the property assigned to is a named property, which is not
+    // __proto__.
     Property* property = assignment->target()->AsProperty();
     ASSERT(property != NULL);
     Literal* literal = property->key()->AsLiteral();
     uint32_t dummy;
     if (literal != NULL &&
         literal->handle()->IsString() &&
+        !String::cast(*(literal->handle()))->Equals(Heap::Proto_symbol()) &&
         !String::cast(*(literal->handle()))->AsArrayIndex(&dummy)) {
       Handle<String> key = Handle<String>::cast(literal->handle());
 
       // Check whether the value assigned is either a constant or matches the
       // name of one of the arguments to the function.
       if (assignment->value()->AsLiteral() != NULL) {
         // Constant assigned.
         Literal* literal = assignment->value()->AsLiteral();
         AssignmentFromConstant(key, literal->handle());
         return;
@@ skipping 3537 matching lines @@
       parser.ParseLazy(script_source, name,
                        start_position, end_position, is_expression);
   return result;
 }
 
 
 #undef NEW
 
 
 } }  // namespace v8::internal