unix: update openbsd/{386,amd64.arm} MAP_* consts
Update the MAP_* consts for openbsd/{386,amd64.arm} on OpenBSD 6.5.
openbsd/arm64 was already generated on OpenBSD 6.5 for CL 173678.
Fixes golang/go#34589
Change-Id: Ie06bdc28ddd39a8c8e4f61137cb060f74c59e1eb
Reviewed-on: https://go-review.googlesource.com/c/sys/+/198157
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Benny Siegert <bsiegert@gmail.com>