LUCENE-5939: Regenerate 3.1.0 backcompat index

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_10@1624658 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-5939: Add changes entry (merged 1624662)

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_10@1624663 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-5939: Fix backcompat test to not look for numerics in <= 3.2 (instead of <= 3.1)

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene_solr_4_10@1624669 13f79535-47bb-0310-9956-ffa450edef68