ZP-756 add compat function for memory_get_peak_usage.

Released under the Affero GNU General Public License (AGPL) version 3.

src/lib/utils/compat.php

@@ -155,8 +155,10 @@ if (!function_exists('memory_get_peak_usage')) {
      * This complementary function will return the value of memory_get_usage();
      * @see http://php.net/manual/en/function.memory-get-usage.php
      * @see http://php.net/manual/en/function.memory-get-peak-usage.php
+     *
+     * @param boolean $real_usage
      */
-    function memory_get_peak_usage() {
+    function memory_get_peak_usage($real_usage = false) {
         ZLog::Write(LOGLEVEL_DEBUG, "memory_get_peak_usage() is not available on this system. The value of memory_get_usage() will be used.");
         return memory_get_usage();
     }