8232230: Suppress warnings on non-serializable non-transient instance fields in java.util.concurrent

Reviewed-by: martin

src/java.base/share/classes/java/util/concurrent/RecursiveTask.java

@@ -71,6 +71,7 @@ public abstract class RecursiveTask<V> extends ForkJoinTask<V> {
     /**
      * The result of the computation.
      */
+    @SuppressWarnings("serial") // Conditionally serializable
     V result;
 
     /**