RFR (XS): 8160024 jdb returns invalid argument count if first parameter to Arrays.asList is null

[serguei.spitsyn at oracle.com]

Please, review this small fix.

Bug: https://bugs.openjdk.java.net/browse/JDK-8160024

JDK webrev:
http://cr.openjdk.java.net/~sspitsyn/webrevs/2016/hotspot/8160024-JDI-eval.jdk1/

The bug is confidential, so the RFR is sent to the confidential mailing
lists.


Summary:

   The JDI incorrectly evaluates the expression: Arrays.asList(null, "a").
   The root cause is a special case in the method MethodImpl.handleVarArgs()
   that has been corrected in order to fix the problem.

   New unit test is included: jdk/test/com/sun/jdi/EvalArraysAsList.sh

Testing:
   Ran new unit test, Jtreg com/sun/jdi and nsk.jdi.testlist.
   All tests are passed.

Thanks,
Serguei