fix broken browser.test_emscripten_api_infloop [ci skip]

Author: kripken

tests/emscripten_api_browser_infloop.cpp

@@ -27,10 +27,10 @@ struct Class {
     instance = this;
 
     EM_ASM({
-      var initial = Runtime.stackSave();
+      var initial = stackSave();
       Module.print('seeing initial stack of ' + initial);
       setTimeout(function() {
-        var current = Runtime.stackSave();
+        var current = stackSave();
         Module.print('seeing later stack of   ' + current);
         assert(current === initial);
       }, 0);