Description:
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When doing simple math, there is a problem with numbers with 2 digits greater then 07 in sums.
It appears to ignore any numbers starting with a zero that are bigger then 07.

Reproduce code:
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<?
$calc = 01 + 03 + 05 + 06 + 07 + 08;
echo "The result is: $calc";
?>

Expected result:
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The result is: 30

Actual result:
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The result is: 22