Differences with NetBSD
Reapply our local patches on top of it
Fix Unicode environement detection
Fix reading a line in unicode environment.
It allows /bin/sh to works in UTF-8 envs
Differential Revision: https://reviews.freebsd.org/D1455
Reviewed by: jilles, pfg
Obtained from: NetBSD [1]
MFC after: 1 month
Relnotes: yes
