RFR 8171503: Nashorn build, test failures with the latest jdk9-dev forest - javadoc target and test target fail

[Sundararajan Athijegannathan]

Please review http://cr.openjdk.java.net/~sundar/8171503/webrev.00/ for 
https://bugs.openjdk.java.net/browse/JDK-8171503

Thanks,
-Sundar