Boost memory_limit at runtime if permitted

bin/composer

@@ -6,7 +6,8 @@ require __DIR__.'/../src/bootstrap.php';
 use Composer\Console\Application;
 
 error_reporting(-1);
-ini_set('display_errors', 1);
+@ini_set('display_errors', 1);
+@ini_set('memory_limit', '512M');
 
 // run the command application
 $application = new Application();