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/SoftReference.java

@@ -56,6 +56,7 @@ package java.lang.ref;
  * prevent its most recently used entries from being discarded by keeping
  * strong referents to those entries, leaving the remaining entries to be
  * discarded at the discretion of the garbage collector.
+ * @param<T> the type of the referent
  *
  * @author   Mark Reinhold
  * @since    1.2