Updates golang/go#19103 (fixes after bundle into std)

Change-Id: I847133e289e210dedf2b89ab529478edc5de11d1
Reviewed-on: https://go-review.googlesource.com/45773
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>