[8u20]: Request for approval - 8035392: cppInterpreter: fix message of NPE

[Lindenmaier, Goetz]

Hi,

please review this change for backport to 8u via ppc-aix-port/stage.
(It could be fixed in 8u, too.  But that would cause need for resolving
when merging with stage.)

The cpp interpreter 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.

changeset: http://hg.openjdk.java.net/jdk9/hs/hotspot/rev/1e820011ee5f
bug:  https://bugs.openjdk.java.net/browse/JDK-8035392
review: http://mail.openjdk.java.net/pipermail/hotspot-dev/2014-February/012641.html

original webrev: http://cr.openjdk.java.net/~goetz/webrevs/8035392-1-nullMsg/

Thanks and best regards,
  Goetz.