N°2651 rollback gitignore for lib tests dirs

Too dangerous ! We'll work properly on this but for 2.8

lib/symfony/http-kernel/Tests/Fixtures/123/Kernel123.php

@@ -0,0 +1,37 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\HttpKernel\Tests\Fixtures\_123;
+
+use Symfony\Component\Config\Loader\LoaderInterface;
+use Symfony\Component\HttpKernel\Kernel;
+
+class Kernel123 extends Kernel
+{
+    public function registerBundles()
+    {
+        return [];
+    }
+
+    public function registerContainerConfiguration(LoaderInterface $loader)
+    {
+    }
+
+    public function getCacheDir()
+    {
+        return sys_get_temp_dir().'/'.Kernel::VERSION.'/kernel123/cache/'.$this->environment;
+    }
+
+    public function getLogDir()
+    {
+        return sys_get_temp_dir().'/'.Kernel::VERSION.'/kernel123/logs';
+    }
+}