LUCENE-5958: add more efficient test

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1625538 13f79535-47bb-0310-9956-ffa450edef68
give MDW verbosity when it throws deterministic exception

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1625540 13f79535-47bb-0310-9956-ffa450edef68