Change record status: 
Project: 
Introduced in branch: 
8.0.x
Introduced in version: 
8.0.0-beta8
Description: 

Admin roles are now stored as part of the role entities itself, no longer as an extern variable.

Drupal 8 (before 8.0.x-beta4)

// Get the admin role.
$admin_role = \Drupal::config('user.settings')->get('admin_role');
// Change the admin role
\Drupal::configFactory()->getEditable('user.settings')->set('admin_role', 'my_new_administrator_role');

Drupal 8

// Get all admin roles.
$admin_roles = \Drupal::entityQuery('user_role')->condition('is_admin', TRUE)->execute();

// Set a specific role to be an admin role.
$role = \Drupal\user\Entity\Role::load('my_new_administrator_role')->set('is_admin', TRUE)->save();
Impacts: 
Site builders, administrators, editors
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