'ListDefinedTags': When trying to find all defined tags.
&$tags: The list of tags.
-'LoadExtensionSchemaUpdates': called by maintenance/updaters.inc when upgrading
-database schema
+'LoadExtensionSchemaUpdates': called during database installation and updates
+&updater: A DatabaseUpdater subclass
'LocalFile::getHistory': called before file history query performed
$file: the file