Issue #2728427 by lussoluca, GroovyCarrot, MiSc, damiankloip: Add compatibility with PHP 7

Author: damiankloip

src/DrupalMemcached.php

@@ -76,8 +76,12 @@ public function getMulti(array $keys) {
       $full_keys[$cid] = $full_key;
     }
 
-    $cas_tokens = NULL;
-    $results = $this->memcache->getMulti($full_keys, $cas_tokens, \Memcached::GET_PRESERVE_ORDER);
+    if (PHP_MAJOR_VERSION === 7) {
+      $results = $this->memcache->getMulti($full_keys, \Memcached::GET_PRESERVE_ORDER);
+    } else {
+      $cas_tokens = NULL;
+      $results = $this->memcache->getMulti($full_keys, $cas_tokens, \Memcached::GET_PRESERVE_ORDER);
+    }
 
     // If $results is FALSE, convert it to an empty array.
     if (!$results) {