copy to bring these files into libc from libcompat. I will enable
them and kill off the libcompat versions on the main branch soon.
PR: step one toward closing misc/6763
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.