This is a simple export/import backport for 8023529: OpenMBeanInfoSupport.equals/hashCode throw NPE
bug: https://bugs.openjdk.java.net/browse/JDK-8023529 jdk 8 changeset: http://hg.openjdk.java.net/jdk8/tl/jdk/rev/e407df8093dcjdk 8 review: http://mail.openjdk.java.net/pipermail/serviceability-dev/2013-September/011535.html
Thanks, Shanliang
