add SuperGlobals test

Author: f.schmitt

tests/rules/variables/allowed/SuperGlobals.php

@@ -0,0 +1,12 @@
+<?php
+// @expectedPass
+
+$GLOBALS=true;
+$_SERVER=true;
+$_GET=true;
+$_POST=true;
+$_FILES=true;
+$_COOKIE=true;
+$_SESSION=true;
+$_REQUEST=true;
+$_ENV=true;