MFC r362664, r362665:

r362664 | imp | 2020-06-26 16:05:23 -0600 (Fri, 26 Jun 2020) | 21 lines
Chroot(2) actually appeared in 7th Edition Unix. ...

r362665 | imp | 2020-06-26 16:23:15 -0600 (Fri, 26 Jun 2020) | 10 lines
Chroot(8) first appeared in 4.3-Reno, not in 4.4 in the BSD world,
but in System III in the AT&T world.

Examination of the TUHS archives shows this was present in 4.3-Reno
and System III.

Reviewed by: 0mp@, allanjude@
MFC After: 3 days
Differential Revision: https://reviews.freebsd.org/D25479