Proposed resolution:

This wording is relative to N4618.

1. Edit [depr.meta.types] as indicated:

   The header <type_traits> has the following addition:

   namespace std {
     template <class T> struct is_literal_type;
     
     template <class T> constexpr bool is_literal_type_v = is_literal_type<T>::value;
   }
   

   -2- Requires: remove_all_extents_t<T> shall be a complete type or (possibly cv-qualified) void.

   -3- Effects: is_literal_type has a base-characteristic of true_type if T is a literal type (3.9), and a basecharacteristic of false_type otherwiseis_literal_type<T> is a UnaryTypeTrait ([meta.rqmts]) with a BaseCharacteristic of true_type if T is a literal type ([basic.types]), and false_type otherwise.

   -?- The behavior of a program that adds specializations for is_literal_type or is_literal_type_v is undefined.