Revert "Issue #2730129 by klausi, jibran, dawehner: DrupalKernel must never...

Revert "Issue #2730129 by klausi, jibran, dawehner: DrupalKernel must never persist service_container for Symfony 3 update"

This reverts commit bfdc7b52.

core/lib/Drupal/Core/DrupalKernel.php

@@ -1227,8 +1227,7 @@ protected function compileContainer() {
     // be automatically reinstantiated. Also include services tagged to persist.
     $persist_ids = array();
     foreach ($container->getDefinitions() as $id => $definition) {
-      // It does not make sense to persist the container itself, exclude it.
-      if ($id !== 'service_container' && ($definition->isSynthetic() || $definition->getTag('persist'))) {
+      if ($definition->isSynthetic() || $definition->getTag('persist')) {
         $persist_ids[] = $id;
       }
     }

core/modules/system/src/Tests/DrupalKernel/DrupalKernelTest.php

@@ -146,11 +146,6 @@ public function testCompileDIC() {
       'pathname' => drupal_get_filename('module', 'service_provider_test'),
       'filename' => NULL,
     ));
-
-    // Check that the container itself is not among the persist IDs because it
-    // does not make sense to persist the container itself.
-    $persist_ids = $container->getParameter('persist_ids');
-    $this->assertFalse(array_search('service_container', $persist_ids));
   }
 
   /**