test: Add the usual Copyright notice.

Fixes #2759.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5570053
diff --git a/test/fixedbugs/bug222.dir/chanbug2.go b/test/fixedbugs/bug222.dir/chanbug2.go
index 73e1667..109581d 100644
--- a/test/fixedbugs/bug222.dir/chanbug2.go
+++ b/test/fixedbugs/bug222.dir/chanbug2.go
@@ -1,2 +1,6 @@
+// Copyright 2009 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
+
 package Bar
 import _ "chanbug"