expr_dup_type
type_t *expr_dup_type(const type_t *);
type_t *ntp = expr_dup_type(tn->tn_type);
type_t *nstp = expr_dup_type(tp1->t_subt);
type_t *ntp = expr_dup_type(tp1);
type_t *tp = expr_dup_type(tn->tn_type);
type_t *ntp = expr_dup_type(gettyp(nt));