Call the specific add() methods for eacj block type

(cherry picked from commit 5176663)

Author: ivancea

x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/aggregation/GroupingAggregatorFunction.java

@@ -88,6 +88,26 @@ default void add(int positionOffset, IntBigArrayBlock groupIds) {
             add(positionOffset, (IntBlock) groupIds);
         }
 
+        /**
+         * Calls an {@code add()} implementation given the specific {@code groupIds} block type.
+         */
+        default void addSpecific(int positionOffset, IntBlock groupIds) {
+            switch (groupIds) {
+                case IntVectorBlock b:
+                    add(positionOffset, b);
+                    break;
+                case IntArrayBlock b:
+                    add(positionOffset, b);
+                    break;
+                case IntBigArrayBlock b:
+                    add(positionOffset, b);
+                    break;
+                default:
+                    add(positionOffset, groupIds);
+                    break;
+            }
+        }
+
         /**
          * Send a batch of group ids to the aggregator. The {@code groupIds}
          * may be offset from the start of the block to allow for sending chunks