HIVE-8304: Tez Reduce-Side GROUP BY Vectorization doesn't copy NULL keys correctly (Matt McCline via Gopal V)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1629067 13f79535-47bb-0310-9956-ffa450edef68
HIVE-8240: VectorColumnAssignFactory support for VARCHAR (Matt McCline, via Gopal V)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1629091 13f79535-47bb-0310-9956-ffa450edef68