Issue #2305839 by jhodgdon, tim.plunkett: Convert hook_element_info() to annotated classes.

core/core.services.yml

core/includes/ajax.inc

core/includes/common.inc

core/includes/form.inc

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

core/lib/Drupal/Core/Render/Annotation/FormElement.php

core/lib/Drupal/Core/Render/Annotation/RenderElement.php

core/lib/Drupal/Core/Render/Element.php

core/lib/Drupal/Core/Render/Element/ElementInterface.php

core/lib/Drupal/Core/Render/Element/FormElement.php

core/lib/Drupal/Core/Render/Element/FormElementInterface.php

core/lib/Drupal/Core/Render/Element/Link.php

core/lib/Drupal/Core/Render/Element/MachineName.php

core/lib/Drupal/Core/Render/Element/RenderElement.php

core/lib/Drupal/Core/Render/Element/Textfield.php

core/lib/Drupal/Core/Render/ElementInfo.php

core/lib/Drupal/Core/Render/ElementInfoInterface.php

core/lib/Drupal/Core/Render/ElementInfoManager.php

core/lib/Drupal/Core/Render/ElementInfoManagerInterface.php

core/lib/Drupal/Core/Render/Plugin/README.txt