RFR(XS): 8035392: cppInterpreter: fix message of NPE

[Lindenmaier, Goetz]

Hi,

we fixed an issue with the cpp interpreter.

It generates a NullPointerException with "" as message. Jck test
api/java_util/Objects/index.html#RequireNonNullMessageSupplier expects
NULL. This is also what the template interpreter uses.

Fix: change "" to NULL.
http://cr.openjdk.java.net/~goetz/webrevs/8035392-1-nullMsg/

Please review and test this change.  It also needs to go to
jdk8u via ppc-aix-port/stage.

Best regards,
  Goetz.