n64 is the default, drop the o32/o64 register assignment conditionals.
Normalize sentinel. Use _MACHINE_*_H_ and _<ARCH>_*_H_ properly and consitently.Discussed and okay drahn@. Okay deraadt@.
Remove advertising clause from UCB licenses; ok deraad@
these should have gone in with the other 64 bit changes
initial mips64