RFR 8071588: The spec for javax.script.ScriptEngineFactory.getProgram() should specify NPEs thrown

[Sundararajan Athijegannathan]

Please review.

Bug: https://bugs.openjdk.java.net/browse/JDK-8071588

jdk webrev: http://cr.openjdk.java.net/~sundar/8071588/jdk/webrev.00/

nashorn webrev:
http://cr.openjdk.java.net/~sundar/8071588/nashorn/webrev.00/

Thanks

-Sundar