HIVE-7338: Create SparkPlanGenerator

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/spark@1614300 13f79535-47bb-0310-9956-ffa450edef68
HIVE-7338: Create SparkPlanGenerator(missing new files in previous commit)

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/spark@1614496 13f79535-47bb-0310-9956-ffa450edef68