HIVE-4813 : Improve test coverage of package org.apache.hadoop.hive.ql.optimizer.pcr (Ivan Veselovsky via Ashutosh Chauhan)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1501099 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd
Merge remote branch 'origin/trunk-gd' into fb-HIVE-4779-trunk-gd