Remove unnecessary coupling between Promise tests and Object.observe

test/mjsunit/es6/debug-promises/events.js

Index: test/mjsunit/es6/debug-promises/events.js
diff --git a/test/mjsunit/es6/debug-promises/events.js b/test/mjsunit/es6/debug-promises/events.js
index a9f94543f40594450e5ec02d9317a0e605b48f23..3fcb22ff2740985d2a22c79e7c3334a184007c60 100644
--- a/test/mjsunit/es6/debug-promises/events.js
+++ b/test/mjsunit/es6/debug-promises/events.js
@@ -116,9 +116,7 @@ function testDone(iteration) {
   }
 
   var iteration = iteration || 0;
-  var dummy = {};
-  Object.observe(dummy, checkResult);
-  dummy.dummy = dummy;
+  %EnqueueMicrotask(checkResult);
 }
 
 testDone();