A hook is needed that allows GlobalBlocking to be given a configurable length list of IP addresses to retroactively globally autoblock. This means that extensions, such as CheckUser, can provide this list to allow the GlobalBlocking extension to perform the global autoblocks.
Note: The hook will differ from the PerformRetroactiveAutoblock, as implementations of the hook will not be expected to perform the autoblocking. This is so that GlobalBlocking can be in charge of determining the duration and scope of the global autoblocks.