Merge branch 'PHP-7.1' into PHP-7.2

* PHP-7.1:
  The SO_PASSCRED constant is conditionally defined

Author: tpunt

ext/sockets/tests/socket_cmsg_credentials.phpt

@@ -11,6 +11,9 @@ die('skip not for Microsoft Windows');
 if (strtolower(substr(PHP_OS, 0, 3)) == 'aix') {
 die('skip not for AIX');
 }
+if (!defined('SO_PASSCRED')) {
+die('skip SO_PASSCRED is not defined');
+}
 --CLEAN--
 <?php
 $path = __DIR__ . "/unix_sock";