tix-build recorded the owner and group as the user building the package,
rather than setting the owner and group to user 0 (root).

tix-install tried to chown extracted files as the owner and group in the
archive, rather than the current user. It also applied the current umask
rather than restoring the same permissions.

This system call has five arguments, of which one is a 64-bit uid_t, and
another is a 64-bit gid_t, which means that 7 registers are needed. However,
x86 only has 5 registers available for system calls. Wrap the system call
with a structure like with mmap(2).

I hereby relicense all my work on Sortix under the ISC license as below.

All Sortix contributions by other people are already under this license,
are not substantial enough to be copyrightable, or have been removed.

All imported code from other projects is compatible with this license.

All GPL licensed code from other projects had previously been removed.

Copyright 2011-2016 Jonas 'Sortie' Termansen and contributors.

Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.