Reduce (some) compile noise of 'unused variable' and 'may be used uninitialized' warnings.
Merge branch 'PHP-5.4' of https://git.php.net/repository/php-src into PHP-5.4

* 'PHP-5.4' of https://git.php.net/repository/php-src:
  Fixed #65431 in zend_exception.c by Sixd