Description:
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Calling apc_store two times in a row with the keys "75" and "6V" issues a "Potential cache slam" warning, although the keys aren't the same.

Reproduce code:
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<?php

$s1 = '75';
$s2 = '6V';

apc_store($s1, 1);
apc_store($s2, 2);

echo apc_fetch($s1) . "\n";
echo apc_fetch($s2) . "\n";


Expected result:
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1
2

Actual result:
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Warning: apc_store(): Potential cache slam averted for key '6V' in /home/seb/tmp/apc.php on line 7
1