http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46724
--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-12-17 08:55:06 UTC --- Ah, the trick is that you keep the artificial PARM_DECL out of DECL_ARGUMENTS as it was and manually add it in var-tracking. To avoid dropping the DECL_NAME test you could perhaps give some artificial name to this PARM_DECL and make it DECL_NAMELESS.
