SQLite 3.6.8 was released in January 2009 and finally brings SAVEPOINT transactions.
Four years later we can safely assume that people have migrated to 3.6.8.
We could also check which other newer SQLite features we can use in order to bring the backends more into par.
Inspired by: * @todo Consider upping to 3.6.8 in Drupal 8 to get SAVEPOINT support.
in core/lib/Drupal/Core/Database/Driver/sqlite/Install/Tasks.php