http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53704
--- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-06-20 08:44:19 UTC --- Because DW_LANG_Fortran90 is already in DWARF2, but DW_LANG_Fortran95 is only in DWARF3 and later. If you request DWARF2 and strictly that, no extensions, which is what Darwin does, then you get what you request.
