so that our release note can reference a simple command to check if
the processor implements ARMv6K or not.

Updates #17082.

Change-Id: I9ca52051e5517394a7cd6b778fb822c3ee435f84
Reviewed-on: https://go-review.googlesource.com/33686
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>