"ant clean test" with nashorn repo using the latest jdk9-dev forest build fails.

* javadoc target from "test" target fails with NoSuchElementException.


javadoc:
[javadoc] Generating Javadoc
[javadoc] Javadoc execution
[javadoc] javadoc: warning - File ignored: "/scratch/srinivas/nashorn/dev/nashorn/src/jdk.dynalink/share/classes/module-info.java" (not yet supported)
[javadoc] javadoc: warning - File ignored: "/scratch/srinivas/nashorn/dev/nashorn/src/jdk.scripting.nashorn/share/classes/module-info.java" (not yet supported)
[javadoc] javadoc: warning - File ignored: "/scratch/srinivas/nashorn/dev/nashorn/src/jdk.scripting.nashorn.shell/share/classes/module-info.java" (not yet supported)
[javadoc] javadoc: warning - Error fetching URL: http://docs.oracle.com/javase/8/docs/api/
[javadoc] 1 error
[javadoc] 4 warnings
[javadoc] javadoc: error - An exception occurred while building a component: PackagesSummary
[javadoc] (java.util.NoSuchElementException)
[javadoc] Please file a bug against the javadoc tool via the Java bug reporting page
[javadoc] (http://bugreport.java.com) after checking the Bug Database (http://bugs.java.com)
[javadoc] for duplicates. Include error messages and the following diagnostic in your report. Thank you.
[javadoc] java.util.NoSuchElementException
[javadoc] at java.base/java.util.RegularEnumSet$EnumSetIterator.next(RegularEnumSet.java:102)

A bug has been filed against javadoc. See also: JDK-8171501

* After working around the javadoc issue [by avoiding to generate javadoc for shell module which has empty exported packages], we get test failures.

Unknown module: jdk.scripting.nashorn.shell specified in --patch-module