[release-branch.go1.14] runtime/race: rebuild netbsd .syso

For #14481
For #37355
For #38321

Change-Id: Idfceaf0e64d340b7304ce9562549a82ebfc27e3c
Reviewed-on: https://go-review.googlesource.com/c/go/+/227867


Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
(cherry picked from commit 3afa7411)
Reviewed-on: https://go-review.googlesource.com/c/go/+/232417


Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>