http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46862
--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-12-09 11:25:08 UTC --- Not sure if we should error out if a TYPE_TRANSPARENT_AGGR doesn't in the end have any fields, or simply mangle them normally if first_field returns NULL, but we shouldn't ICE on it.