8285676: Add missing @param tags for type parameters on classes and interfaces

Reviewed-by: wetmore, smarks, dfuchs, prr, alanb, mchung

src/java.base/share/classes/java/lang/ref/WeakReference.java

@@ -40,6 +40,7 @@ package java.lang.ref;
  * weakly-reachable objects to be finalizable.  At the same time or at some
  * later time it will enqueue those newly-cleared weak references that are
  * registered with reference queues.
+ * @param<T> the type of the referent
  *
  * @author   Mark Reinhold
  * @since    1.2