Updates golang/go#25023

Change-Id: Icd37dfef1b9558b0e774f1637c5566fb444666d5
Reviewed-on: https://go-review.googlesource.com/111679Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>