Follow 'place children last' convention for GeneratedAggregate

Author: JoshRosen

sql/core/src/main/scala/org/apache/spark/sql/execution/GeneratedAggregate.scala

@@ -41,16 +41,16 @@ case class AggregateEvaluation(
  *                ensure all values where `groupingExpressions` are equal are present.
  * @param groupingExpressions expressions that are evaluated to determine grouping.
  * @param aggregateExpressions expressions that are computed for each group.
- * @param child the input data source.
  * @param unsafeEnabled whether to allow Unsafe-based aggregation buffers to be used.
+ * @param child the input data source.
  */
 @DeveloperApi
 case class GeneratedAggregate(
     partial: Boolean,
     groupingExpressions: Seq[Expression],
     aggregateExpressions: Seq[NamedExpression],
-    child: SparkPlan,
-    unsafeEnabled: Boolean)
+    unsafeEnabled: Boolean,
+    child: SparkPlan)
   extends UnaryNode {
 
   override def requiredChildDistribution: Seq[Distribution] =

sql/core/src/main/scala/org/apache/spark/sql/execution/SparkStrategies.scala

@@ -136,13 +136,13 @@ private[sql] abstract class SparkStrategies extends QueryPlanner[SparkPlan] {
             partial = false,
             namedGroupingAttributes,
             rewrittenAggregateExpressions,
+            unsafeEnabled,
             execution.GeneratedAggregate(
               partial = true,
               groupingExpressions,
               partialComputation,
-              planLater(child),
-              unsafeEnabled),
-            unsafeEnabled) :: Nil
+              unsafeEnabled,
+              planLater(child))) :: Nil
 
       // Cases where some aggregate can not be codegened
       case PartialAggregation(