Description:
------------
verify type fail will leak memory if the op1 of zend_return is IS_CONST (only visible run without opcache due to interned-string-fy in opcache)

Test script:
---------------
<?php

function getNumber() : int {
    return "foo";
}

try {
    getNumber();
} catch (TypeError $e) {

}
?>

Expected result:
----------------
non memleak

Actual result:
--------------
$ /home/huixinchen/local/php7/bin/php -n /tmp/1.php
[Wed Sep 23 13:59:30 2015]  Script:  '/tmp/1.php'
/home/huixinchen/opensource/php-7.0/Zend/zend_string.h(121) :  Freeing 0x7FFFF8059B00 (32 bytes), script=/tmp/1.php
=== Total 1 memory leaks detected ===