This enables an optimization possible if the script compiler does not have to preserve the LSL rule that right-hand operands must be evaluated before left-hand operands.
For example, if your script contains code such as:
list x = [ 1, 2, 3 ]; x = (x = ) + x + [ 4, 5, 6 ];
... and expects x = [ 1, 2, 3, 4, 5, 6 ] then you cannot use this option.
But if your script does not contain code that has operand evaluation order dependencies (as is the case for many common programming languages) then you can enable this optimization by including this line before any code in your script: