This pulls in two new commits: a fix for a test broken on plan9 and a
correction to a comment.

Change-Id: I31cf046a5073872714c758894732b2fcc800ab6b
Reviewed-on: https://go-review.googlesource.com/c/go/+/214289
Run-TryBot: Jay Conrod <jayconrod@google.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>