HIVE-8547 : CBO and/or constant propagation breaks partition_varchar2 test (Sergey Shelukhin, reviewed by Ashutosh Chauhan)

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/branch-0.14@1633716 13f79535-47bb-0310-9956-ffa450edef68