Description:
------------
@unserialize() throws E_NOTICE with custom handler

Reproduce code:
---------------
<?php
function myErrorHandler($errno, $errmsg, $filename, $linenum) {
	if ($errno == 0) return;
	$error_type = array(0 => 'No Error', 8 => 'Notice'); // just the ones we need...
	echo '<b>' . $error_type[$errno] . '</b>: ' . $errmsg . ' in <b>' . $filename . '</b> on line <b>' . $linenum . '</b><br>' . chr(10);
}
$a = 'abc123';
error_reporting(E_ALL);

$b = unserialize($a); // throws error because $a is not unserializable
if ($b === false) {echo 'failed!<br>';} else {echo $b . '<br>';}
$b = @unserialize($a); // @ suppresses error
if ($b === false) {echo 'failed!<br>';} else {echo $b . '<br>';}

set_error_handler('myErrorHandler');

$b = unserialize($a); // throws error because $a is not unserializable
if ($b === false) {echo 'failed!<br>';} else {echo $b . '<br>';}
$b = @unserialize($a); // should throw nothing but throws Notice!
if ($b === false) {echo 'failed!<br>';} else {echo $b . '<br>';}
?>

Expected result:
----------------
E_NOTICE errors should not happen when prepending @: the custom handler should receive $errno = 0

Actual result:
--------------
E_NOTICE error