magic C promotion to silently do so for us.

was the first file tested with my type checker with the anal
pointer attribute checking turned on.

user space access functions. This allows the type checker
to check proper usage.

checking, these end up being no-ops, but they get enabled
by the type checker as special address_space attributes.

There is a stunning bug.

Previously, it was done automatically by the `reti' isntruction upon
returning from the kernel, but that doesn't do the correct thing in
various cases, for instance if there's a context switch, or a softirq.

Allows for the non standard cascade