op_unary
$$ = op_unary(ITM_OP_EXPR, $1, sizeof (itm_expr_t));
$$ = op_unary(ITM_OP_ERROR, $2, sizeof (itm_expr_t));
$$ = op_unary(ITM_OP_DISCARD, $2, sizeof (itm_expr_t));
$$ = op_unary(ITM_OP_OUT_D, $3, sizeof (itm_expr_t));
$$ = op_unary(ITM_OP_OUT_S, $3, sizeof (itm_expr_t));
$$ = op_unary(ITM_OP_OUT_R, $3, sizeof (itm_expr_t));
$$ = op_unary(ITM_OP_OUT_INVD, $3, sizeof (itm_expr_t));
$$ = op_unary(ITM_OP_OUT, $3, sizeof (itm_expr_t));
$$ = op_unary(ITM_OP_PRINTCHR, $2, sizeof (itm_expr_t));
$$ = op_unary(ITM_OP_PRINTHD, $2, sizeof (itm_expr_t));
$$ = op_unary(ITM_OP_PRINTINT, $2, sizeof (itm_expr_t));
itmc_obj_t *op_unary(itm_op_type_t, void *, size_t);