Description:
------------
If pass a numeric array with gaps in keys as argument of PDOStatement::execute(), DB returns not all matched rows.

Test script:
---------------
$needValues = [
    'aaa',
    'bbb',
    'ccc',
    'bbb', // Copy of key 1.
    'ddd'
];
$needValues = array_unique($needValues); // Produce array with keys gap
// $needValues = array_values(array_unique($needValues)); // No keys gap => NO BUG

$sql = 'SELECT "value" FROM "values_table" WHERE "value" IN (%s)';
$sql = sprintf($sql, implode(',', array_fill(0, count($needValues), '?')));
$stmt = $postgresDb->prepare($sql);
$stmt->execute($needValues);

var_dump($stmt->fetchAll());

Expected result:
----------------
"ddd"
"ccc"
"bbb"
"aaa"

Actual result:
--------------
"ccc"
"bbb"
"aaa"