N°2651 rollback gitignore for lib tests dirs

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

lib/symfony/debug/Tests/Fixtures/AnnotatedClass.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace Symfony\Component\Debug\Tests\Fixtures;
+
+class AnnotatedClass
+{
+    /**
+     * @deprecated since version 3.4.
+     */
+    public function deprecatedMethod()
+    {
+    }
+}