Description:
------------
When several autoload handlers are registered with spl_autoload_register, and the class starting with T_NS_SEPARATOR (\) AND created using the variable class name is autoloaded, spl_autoload does not stop at the first successful item and goes thru the whole stack.


Reproduce code:
---------------
// Source files:
// foo-bar1.php
namespace foo; class bar1 {}

// foo-bar2.php
namespace foo; class bar2 {}

// foo-baz1.php
namespace foo; class baz1 {}

// foo-baz2.php
namespace foo; class baz2 {}

// test.php
function autoload1($class) {
    echo "autoload1($class) is called!\n";
    $path = array_filter(explode('\\', $class), 'strlen');
    require join('-', $path) . ".php";
}
function autoload2($class) {
    echo "autoload2($class) is called!\n";
    $path = array_filter(explode('\\', $class), 'strlen');
    require join('-', $path) . ".php";
}
spl_autoload_register('autoload1');
spl_autoload_register('autoload2');

$f = new foo\bar1;
$f = new \foo\baz1;
$class = "foo\\bar2"; $f = new $class;
$class = "\\foo\\baz2"; $f = new $class;


Expected result:
----------------
autoload1(foo\bar1) is called!
autoload1(foo\baz1) is called!
autoload1(foo\bar2) is called!
autoload1(\foo\baz2) is called!


Actual result:
--------------
autoload1(foo\bar1) is called!
autoload1(foo\baz1) is called!
autoload1(foo\bar2) is called!
autoload1(\foo\baz2) is called!
autoload2(\foo\baz2) is called!
PHP Fatal error:  Cannot redeclare class foo\baz2