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/PhantomReference.java

@@ -45,6 +45,7 @@ import jdk.internal.vm.annotation.IntrinsicCandidate;
  * phantom reference always returns {@code null}.
  * The {@link #refersTo(Object) refersTo} method can be used to test
  * whether some object is the referent of a phantom reference.
+ * @param<T> the type of the referent
  *
  * @author   Mark Reinhold
  * @since    1.2