* Pass the correct virtual address when demoting a superpage
* Use the correct l3 table after demoting a superpage
* Remove an invalid KASSERT hit demoting then promoting a superpage [1]
With this it is believed that superpages on arm64 is stable.
Reported by: [1] cognet
Obtained from: ABT Systems Ltd
MFC after: 1 week
Sponsored by: The FreeBSD Foundation