The not exist field.module.css is added to the page

The field.module.css is not exists. Neither in field module nor in field_ui module, but the hook_page_build() implementation in field module adds it to the page.

/**
 * Implements hook_page_build().
 */
function field_page_build(&$page) {
  $path = drupal_get_path('module', 'field');
  $page['#attached']['css'][$path . '/css/field.module.css'] = array('every_page' => TRUE);
}

In the field module there is no any CSS file.
The "field.module.css" is also mentioned in a comment in template_preprocess_field()