private RelNode genSelectRelNode(List<RexNode> calciteColLst, RowResolver out_rwsch,
            RelNode srcRel) throws CalciteSemanticException {
      return genSelectRelNode(calciteColLst, out_rwsch, srcRel, null);
    }
Generate OB RelNode and input Select RelNode that should be used to
introduce top constraining Project. If Input select RelNode is not
present then don't introduce top constraining select.

@param qb
@param selPair
@param outermostOB
@return RelNode OB RelNode
@throws SemanticException
ql/src/java/org/apache/hadoop/hive/ql/parse/CalcitePlanner.java