For #22095

Change-Id: I660080279692b74669c45f42c28cccff71bd33b5
Reviewed-on: https://go-review.googlesource.com/68930Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>