Issue #3426789 by mondrake, smustgrave: DatabaseDriver::load should have a...

Issue #3426789 by mondrake, smustgrave: DatabaseDriver::load should have a non-service alternative for class loading

core/lib/Drupal/Core/Extension/DatabaseDriver.php

@@ -90,7 +90,12 @@ public function getPath() {
    */
   public function load() {
     if (!isset($this->classLoader)) {
-      $this->classLoader = \Drupal::service('class_loader');
+      if (\Drupal::hasContainer() && \Drupal::hasService('class_loader')) {
+        $this->classLoader = \Drupal::service('class_loader');
+      }
+      else {
+        $this->classLoader = require DRUPAL_ROOT . '/autoload.php';
+      }
       $this->classLoader->addPsr4($this->getNamespace() . '\\', $this->getPath());
       foreach (($this->getAutoloadInfo()['dependencies'] ?? []) as $dependency) {
         $this->classLoader->addPsr4($dependency['namespace'] . '\\', $dependency['autoload']);