OPENJPA-2487.  This patch provided by Romain Manni-Bucau looks good.  As stated in the Comments, this patch by itself is not sufficient for Java 8 runtime support, but it is a crucial step.  Follow the linked JIRAs for additional fixes required to fully support Java 8.

git-svn-id: https://svn.apache.org/repos/asf/openjpa/trunk@1586647 13f79535-47bb-0310-9956-ffa450edef68