Merge branch 'PHP-5.4' of https://git.php.net/repository/php-src into PHP-5.4

# By Pierre Joye
# Via Pierre Joye
* 'PHP-5.4' of https://git.php.net/repository/php-src:
  fix #66872, invalid argument crashes gmp_testbit
  fix #66872, invalid argument crashes gmp_testbit
  add vc12 (2013)