[Bug fortran/66605] -Wunused-parameter causes internal compiler error with gfortran 5.1.0

[manu at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66605

--- Comment #6 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
Another alternative is to add support for printing %D to gfc_format_decoder, it
is a matter of adding something like:

case 'D':
if (DECL_NAME (t))
{
          pp_string (pp, lang_hooks.decl_printable_name (t, 2));
          return true;
}