HIVE-6664. Vectorized variance computation differs from row mode computation. (jitendra, reviewed by Eric Hanson)

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/branch-0.13@1578626 13f79535-47bb-0310-9956-ffa450edef68
HIVE-6680. Decimal128#update(Decimal128 o, short scale) should adjust the unscaled value. (jitendra, reviewed by Remus Rusanu)

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/branch-0.13@1578627 13f79535-47bb-0310-9956-ffa450edef68