QPID-5723: fix compilation under JDK 8 (somehow..?)

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1590255 13f79535-47bb-0310-9956-ffa450edef68
QPID-5723: fix JavaScript issues to enable evaluation under the new engine in JDK 8

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1590256 13f79535-47bb-0310-9956-ffa450edef68