DERBY-6256: Commit derby-6256-02-aa-allowParentTags.diff, allowing XmlVTIs to inherit columns from outer xml elements in which the primary row element is nested.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1491490 13f79535-47bb-0310-9956-ffa450edef68