Implement swap64 with the bswapq instruction.  (Commit stolen from mikeb@) Add missing __statement modifiers and correct %1 to %0 in the asm.
Implement swap64 with the bswapq instruction.  (Commit stolen from mikeb@)
Add missing __statement modifiers and correct %1 to %0 in the asm.

ok mikeb@, pirofti@, drahn@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars