Added foldable support to CreateArray

Author: gvramana

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/complexTypes.scala

@@ -107,7 +107,9 @@ case class GetField(child: Expression, fieldName: String) extends UnaryExpressio
  */
 case class CreateArray(children: Seq[Expression]) extends Expression {
   override type EvaluatedType = Any
-
+  
+  override def foldable = !children.exists(!_.foldable)
+  
   lazy val childTypes = children.map(_.dataType).distinct
 
   override lazy val resolved =