HACK: memory: add global for fault addresses

Store the latest unassigned access address in a global for all to know.

Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
misc: fake_ram: redesign

Get the latest bad access address on a read to the control region.

Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>