decl_addfun
$$ = decl_addfun($1, $3);
$$ = decl_addfun($1, NULL);
static decl_t *decl_addfun(decl_t *, decl_t *);
$$ = decl_addfun($1, $3);
$$ = decl_addfun(decl_Construct(), $2);
$$ = decl_addfun($1, NULL);
$$ = decl_addfun(decl_Construct(), NULL);