8213154: Update copyright headers of files in src tree that are missing Classpath exception

Reviewed-by: andrew

src/share/classes/sun/security/ssl/ExtendedMasterSecretExtension.java

 /*
- * Copyright (c) 2017, Red Hat, Inc. and/or its affiliates.
- *
+ * Copyright (c) 2017, Red Hat, Inc.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or