The comment says 'DΟ NΟT SUBMIT', and that text being in a file can cause
automated errors or warnings when trying to check the Go sources into other
source control systems.

(We reject that string in CL commit messages, which I've avoided here
by changing the O's to Ο's above.)

Change-Id: I6cdd57a8612ded5208f05a8bd6b137f44424a030
Reviewed-on: https://go-review.googlesource.com/22434
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>