Change record status: 
Project: 
Introduced in branch: 
8.x
Description: 

This change record has been updated based on https://www.drupal.org/node/2302893.

hook_menu_link_defaults() was an interim function in Drupal 8. It is now removed. drupal.org documentation has been updated to reflect this new change: https://drupal.org/node/2122241

Previously

 
 /**
 * Implements hook_menu_link_defaults().
 */
function block_menu_link_defaults() {
  $links['block.admin_display'] = array(
    'link_title' => 'Block layout',
    'parent' => 'system.admin_structure',
    'description' => 'Configure what block content appears in your site\'s sidebars and other regions.',
    'route_name' => 'block.admin_display',
  );

  return $links;
}

After

core/modules/book/book.links.menu.yml

book.admin:
  title: Books
  description: 'Manage your site''s book outlines.'
  parent: system.admin_structure
  route_name: book.admin
Impacts: 
Module developers
Updates Done (doc team, etc.)
Online documentation: 
Not done
Theming guide: 
Not done
Module developer documentation: 
Not done
Examples project: 
Not done
Coder Review: 
Not done
Coder Upgrade: 
Not done
Other: 
Other updates done