N°2651 rollback gitignore for lib tests dirs

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

lib/symfony/debug/Tests/phpt/exception_rethrown.phpt

@@ -0,0 +1,35 @@
+--TEST--
+Test rethrowing in custom exception handler
+--FILE--
+<?php
+
+namespace Symfony\Component\Debug;
+
+$vendor = __DIR__;
+while (!file_exists($vendor.'/vendor')) {
+    $vendor = \dirname($vendor);
+}
+require $vendor.'/vendor/autoload.php';
+
+if (true) {
+    class TestLogger extends \Psr\Log\AbstractLogger
+    {
+        public function log($level, $message, array $context = [])
+        {
+            echo $message, "\n";
+        }
+    }
+}
+
+set_exception_handler(function ($e) { echo 123; throw $e; });
+ErrorHandler::register()->setDefaultLogger(new TestLogger());
+ini_set('display_errors', 1);
+
+throw new \Exception('foo');
+?>
+--EXPECTF--
+Uncaught Exception: foo
+123
+Fatal error: Uncaught %s:25
+Stack trace:
+%a