Remove the entire idea of fasttrap interrupts since V9 traps are really cheap,
the CPUs are really fast, and the completely different trap frames would make
these handlers really difficult to implement.
pmap_changeprot() was only used by the clock and one other place; deprecate it.
probeget() and probeset() now take 64-bit addresses even in 32-bit mode so we
can probe IO locations by physical addresses.
Some pmap cleanup.
Some more copyright cleanup.
eeh