Moved global XMLDocument annotation

From assertInstanceOf to test suite

@@ -849,7 +849,6 @@ Tester.prototype.assertType = function assertType(subject, type, message) {
  */
 Tester.prototype.assertInstanceOf = function assertInstanceOf(subject, constructor, message) {
     "use strict";
-    /*global XMLDocument */
     if (utils.betterTypeOf(constructor) !== "function") {
         throw new CasperError('Subject is null or undefined.');
     }

@@ -25,6 +25,7 @@ casper.test.begin('utils.betterTypeOf() tests', 10,  function(test) {
 });
 
 casper.test.begin('utils.betterInstanceOf() tests', 13,  function(test) {
+    /*global XMLDocument*/
     // need two objects to test inheritance
     function Cow(){} var daisy = new Cow();
     function SuperCow(){} SuperCow.prototype = new Cow(); var superDaisy = new SuperCow();