Add current user roles as classes in body

Closes #3524122

core/modules/user/src/Hook/UserHooks.php

@@ -10,6 +10,7 @@
 use Drupal\Component\Assertion\Inspector;
 use Drupal\user\RoleInterface;
 use Drupal\Component\Render\PlainTextOutput;
+use Drupal\Component\Utility\Html;
 use Drupal\Core\Session\AccountInterface;
 use Drupal\image\Plugin\Field\FieldType\ImageItem;
 use Drupal\Core\Render\Element;
@@ -220,6 +221,12 @@ public function templatePreprocessDefaultVariablesAlter(&$variables): void {
     unset($variables['user']->pass, $variables['user']->sid, $variables['user']->ssid);
     $variables['is_admin'] = $user->hasPermission('access administration pages');
     $variables['logged_in'] = $user->isAuthenticated();
+    $roles = $user->getRoles();
+    $all_roles = '';
+    foreach ($roles as $role) {
+      $all_roles .= Html::cleanCssIdentifier($role) . '-role ';
+    }
+    $variables['roles'] = trim($all_roles);
   }
 
   /**