RFR(S): JDK-8152950 BasicLauncherTest.java fails due to type error

[Dmitry Samersoff]

Everybody,

Please review the fix.

http://cr.openjdk.java.net/~dsamersoff/JDK-8152950/webrev.03/

This fix cleanup the test and improve error handling in CLHSDB launcher.

The root of the problem is that in modular world nashhorn can't access
module internal packages ever if they are public. (see details in bug
report).

Complete fix requires significant efforts and it will be done under
separate CR (JDK-8157947).

-Dmitry

-- 
Dmitry Samersoff
Oracle Java development team, Saint Petersburg, Russia
* I would love to change the world, but they won't give me the sources.