If O_CREAT is specified, the last component of the path argument can
contain invalid characters, and return EINVAL on some file systems.
PR: 281033
Differential revision: https://reviews.freebsd.org/D46450
MFC after: 1 week
Remove core system call implementations and documentation to lib/libsys
and lib/libsys/<arch> from lib/libc/sys and lib/libc/<arch>/<sys>.
Update paths to allow libc to find them in their new home.
Reviewed by: kib, emaste, imp
Pull Request: https://github.com/freebsd/freebsd-src/pull/908