Add gc_mem_caches() call for PHP7 after itoken_get_all() as new memory manager will not release small buckets to OS automatically

Author: Peter Ward

Kernel.php

@@ -733,6 +733,12 @@ public static function stripComments($source)
 
         $output .= $rawChunk;
 
+        if (PHP_VERSION_ID >= 70000) {
+            // PHP 7 memory manager will not release after token_get_all(), see https://bugs.php.net/70098
+            unset($tokens, $rawChunk);
+            gc_mem_caches();
+        }
+
         return $output;
     }