The proto_test tests are failing on NetBSD:

https://build.golang.org/log/a3a577144ac48c6ef8e384ce6a700ad30549fb78

the failures seem similar to previous failures on Android:

https://build.golang.org/log/b5786e0cd6d5941dc37b6a50be5172f6b99e22f0

The Android failures where fixed by CL 37896. This CL is an attempt
to fix the NetBSD failures with a similar fix.

Change-Id: I3834afa5b32303ca226e6a31f0f321f66fef9a3f
Reviewed-on: https://go-review.googlesource.com/38637Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>