Fix old friend declaration

Author: frederick-vs-ja

libcxx/include/__iterator/static_bounded_iter.h

@@ -273,7 +273,7 @@ struct __static_bounded_iter {
 private:
   template <class>
   friend struct pointer_traits;
-  template <class, size_t, class>
+  template <class, size_t>
   friend struct __static_bounded_iter;
   __static_bounded_iter_storage<_Iterator, _Size> __storage_;