8055870: iteration fails if index var is not used
Reviewed-by: hannesw, lagergren
SyntaxError:33:Expected l-value but found +
++ +3
^
SyntaxError:33:Expected l-value but found -
++ -7
^
SyntaxError:33:Expected l-value but found +
-- +2
^
SyntaxError:33:Expected l-value but found -
-- -8
^