Updates #6239
Updates #27707

Change-Id: I0a62c1374db485dd830bf02e59625997d9247fc3
Reviewed-on: https://go-review.googlesource.com/c/go/+/203890
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>