8193031: Collections.addAll is likely to perform worse than Collection.addAll

Reviewed-by: plevart

src/java.base/share/classes/java/util/Collections.java

@@ -5562,9 +5562,8 @@ public class Collections {
     /**
      * Adds all of the specified elements to the specified collection.
      * Elements to be added may be specified individually or as an array.
-     * The behavior of this convenience method is identical to that of
-     * {@code c.addAll(Arrays.asList(elements))}, but this method is likely
-     * to run significantly faster under most implementations.
+     * The behaviour of this convenience method is similar to that of
+     * {@code cc.addAll(Collections.unmodifiableList(Arrays.asList(elements)))}.
      *
      * <p>When elements are specified individually, this method provides a
      * convenient way to add a few elements to an existing collection: