Bug 176963 Subquery's resultSetExpressions is not consistent between generate and present time.
In generate time, subquery will add the parent query's column binding to its own resultSetExpressions. While in present time, it only has the ones of itself.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/PreparedQuery.java
private     ExpressionCompiler 		expressionCompiler;
	private 	IPreparedQueryService 	queryService;
	
	private  	AggregateTable			aggrTable;
	private 	Map 					appContext;
	
	
	private 	HashMap 				subQueryMap;
	
	private 	HashMap 				subQueryDefnMap;
	
	private 	static Logger logger = Logger.getLogger( DataEngineImpl.class.getName( ) );
	
	private 	ExprManager 			exprManager;
	
	/**
	 * @param deContext
	 * @param scope
	 * @param queryDefn
	 * @param queryService
	 * @param appContext
	 * @throws DataException
	 */
	PreparedQuery( DataEngineSession session, DataEngineContext deContext,
			IBaseQueryDefinition queryDefn, IPreparedQueryService queryService,
			Map appContext ) throws DataException
	{
		logger.logp( Level.FINE,
				PreparedQuery.class.getName( ),
				"PreparedQuery",