HIVE-8412: Make reduce side join work for all join queries [Spark Branch]

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/spark@1630617 13f79535-47bb-0310-9956-ffa450edef68
HIVE-8275: Introduce MapInput encapsulating a Hadoop RDD [Spark Branch]

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/spark@1630642 13f79535-47bb-0310-9956-ffa450edef68