HIVE-6924 : MapJoinKeyBytes::hashCode() should use Murmur hash (Sergey Shelukhin, reviewed by Ashutosh Chauhan and Gopal V)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1589330 13f79535-47bb-0310-9956-ffa450edef68