See https://golang.org/cl/20346

Updates golang/go#14660

Change-Id: Ia974e70cdcb240ae1df0018a07595c4d1dcd422a
Reviewed-on: https://go-review.googlesource.com/20347Reviewed-by: Sameer Ajmani <sameer@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>