Proposed resolution:

This wording is relative to the FDIS.

1. Change [iostreams.base.overview], header <ios> synopsis as indicated:

   #include <iosfwd>
   namespace std {
     […]
     error_code make_error_code(io_errc e) noexcept;
     error_condition make_error_condition(io_errc e) noexcept;
     const error_category& iostream_category() noexcept;
   }
   

2. Change the prototype declarations in [error.reporting] as indicated:

   error_code make_error_code(io_errc e) noexcept;
   

   -1- Returns: error_code(static_cast<int>(e), iostream_category()).

   error_condition make_error_condition(io_errc e) noexcept;
   

   -2- Returns: error_condition(static_cast<int>(e), iostream_category()).

   const error_category& iostream_category() noexcept;
   

   -3- Returns: A reference to an object of a type derived from class error_category.

   -4- The object’s default_error_condition and equivalent virtual functions shall behave as specified for the class error_category. The object’s name virtual function shall return a pointer to the string "iostream".