test: silence/coalesce some tests

Add copyright notice to nilptr.go.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5139048
diff --git a/test/nilptr.go b/test/nilptr.go
index 41d8f23..6cf2192 100644
--- a/test/nilptr.go
+++ b/test/nilptr.go
@@ -1,5 +1,9 @@
 // $G $D/$F.go && $L $F.$A && ./$A.out
 
+// Copyright 2011 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 main
 
 import "unsafe"