Filesystem API: Check PHP_OS_FAMILY instead of php_uname() in Pcl…

…Zip.

The `php_uname()` function can be disabled on some hosts, in which case the call fails.

The `PHP_OS_FAMILY` constant indicates the operating system family PHP was built for, and is available as of PHP 7.2.0.

Reference: [https://www.php.net/manual/en/reserved.constants.php#constant.php-os-family PHP Manual: Predefined Constants: PHP_OS_FAMILY].

Follow-up to [6779], [57985], [58678], [58684].

Props daymobrew, costdev, desrosj.
Fixes #57711.

git-svn-id: https://develop.svn.wordpress.org/trunk@59506 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/includes/class-pclzip.php

@@ -5714,7 +5714,7 @@ function PclZipUtilOptionText($p_option)
   // --------------------------------------------------------------------------------
   function PclZipUtilTranslateWinPath($p_path, $p_remove_disk_letter=true)
   {
-    if (stristr(php_uname(), 'windows')) {
+    if (PHP_OS_FAMILY == 'Windows') {
       // ----- Look for potential disk letter
       if (($p_remove_disk_letter) && (($v_position = strpos($p_path, ':')) != false)) {
           $p_path = substr($p_path, $v_position+1);