[DependencyInjection] made a small speed optimization

src/Symfony/Components/DependencyInjection/Dumper/PhpDumper.php

@@ -306,7 +306,9 @@ EOF;
    */
   public function __construct()
   {
-    parent::__construct(\$this->getDefaultParameters());
+    parent::__construct();
+
+    \$this->parameters = \$this->getDefaultParameters();
   }
 
 EOF;