Merged revision(s) 1624073 from lucene/dev/branches/branch_4x:
LUCENE-5934: Fix backwards compatibility for 4.0 indexes.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1624089 13f79535-47bb-0310-9956-ffa450edef68
SOLR-6452: StatsComponent's stat 'missing' will work on fields with docValues=true and indexed=false

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1624091 13f79535-47bb-0310-9956-ffa450edef68