Fix type hint in tablesort class.

core/includes/Drupal/Database/Database.php

@@ -144,7 +144,7 @@ final public static function getLog($logging_key, $key = 'default') {
    * @param $key
    *   The database connection key. Defaults to NULL which means the active key.
    *
-   * @return DatabaseConnection
+   * @return Connection
    *   The corresponding connection object.
    */
   final public static function getConnection($target = 'default', $key = NULL) {

core/includes/tablesort.inc

 <?php
 
+use Drupal\Database\Connection;
 use Drupal\Database\Query\SelectExtender;
 use Drupal\Database\Query\SelectInterface;
 
@@ -23,7 +24,7 @@ class TableSort extends SelectExtender {
    */
   protected $header = array();
 
-  public function __construct(SelectInterface $query, DatabaseConnection $connection) {
+  public function __construct(SelectInterface $query, Connection $connection) {
     parent::__construct($query, $connection);
 
     // Add convenience tag to mark that this is an extended query. We have to