doc/progs: use test/run.go for testing on Windows
cgo[1-4].go, go1.go couldn't be tested now
(cgo[1-4].go can only be tested when cgo is enabled, go1.go
contain a list of filenames in the current directory)
R=golang-dev, alex.brainman, rsc
CC=golang-dev
https://golang.org/cl/6218048
diff --git a/doc/progs/image_package4.go b/doc/progs/image_package4.go
index c46fddf..ec0e461 100644
--- a/doc/progs/image_package4.go
+++ b/doc/progs/image_package4.go
@@ -1,3 +1,5 @@
+// cmpout
+
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
