only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/taxonomy/taxonomy.install
@@ -0,0 +1,24 @@
+<?php
+
+/**
+ * @file
+ * Install, update and uninstall functions for the Taxonomy module.
+ */
+
+/**
+ * @addtogroup updates-8.3.x
+ * @{
+ */
+
+/**
+ * Update the parent field and make its definition computed.
+ */
+function taxonomy_update_8300() {
+  $field_definitions = \Drupal::service('entity_field.manager')->getBaseFieldDefinitions('comment');
+  $field_definitions['parent']->setComputed(TRUE);
+  \Drupal::service('entity.definition_update_manager')->updateFieldStorageDefinition($field_definitions['parent']);
+}
+
+/**
+ * @} End of "addtogroup updates-8.3.x".
+ */