Revert of Issue #1998638, since it broke drush si and other command-line scripts.

core/includes/ajax.inc

core/includes/bootstrap.inc

core/includes/common.inc

core/includes/form.inc

core/includes/install.core.inc

core/includes/language.inc

core/includes/pager.inc

core/includes/session.inc

core/lib/Drupal/Component/Utility/Url.php

core/lib/Drupal/Core/Ajax/AjaxResponse.php

...rupal/Core/EventSubscriber/RedirectResponseSubscriber.php

core/lib/Drupal/Core/Form/FormBuilder.php

core/lib/Drupal/Core/Form/FormBuilderInterface.php

...les/aggregator/lib/Drupal/aggregator/Form/OpmlFeedAdd.php

...odules/config/lib/Drupal/config/Form/ConfigImportForm.php

...dules/editor/lib/Drupal/editor/Form/EditorImageDialog.php

...odules/editor/lib/Drupal/editor/Form/EditorLinkDialog.php

core/modules/file/file.module

...modules/node/lib/Drupal/node/Plugin/Search/NodeSearch.php

.../search/lib/Drupal/search/Controller/SearchController.php