HIVE-8793: Refactor to make splitting SparkWork a physical resolver [Spark Branch] (Rui via Xuefu)

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/spark@1638907 13f79535-47bb-0310-9956-ffa450edef68
HIVE-8780: insert1.q and ppd_join4.q hangs with hadoop-1 [Spark Branch] (Chengxiang via Xuefu)

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/spark@1639241 13f79535-47bb-0310-9956-ffa450edef68
Merge remote-tracking branch 'upstream/spark' into spark