Drupal 8.0.0 beta 12. More info: https://www.drupal.org/node/2514176

core/lib/Drupal/Component/Uuid/Pecl.php

@@ -0,0 +1,21 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Component\Uuid\Pecl.
+ */
+
+namespace Drupal\Component\Uuid;
+
+/**
+ * UUID implementation using the PECL extension.
+ */
+class Pecl implements UuidInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function generate() {
+    return uuid_create(UUID_TYPE_DEFAULT);
+  }
+}