Revert of Promises: Make PromiseSet operation monomorphic

src/js/promise.js

Index: src/js/promise.js
diff --git a/src/js/promise.js b/src/js/promise.js
index f5b39b4048dd5da161a31ccedc7838abdbe65225..93d0e0e15c2669b95f7c11105e4d9aee315830b5 100644
--- a/src/js/promise.js
+++ b/src/js/promise.js
@@ -149,8 +149,7 @@
       var deferreds = GET_PRIVATE(promise, promiseDeferredReactionsSymbol);
       PromiseEnqueue(value, tasks, deferreds, status);
     }
-    SET_PRIVATE(promise, promiseStateSymbol, status);
-    SET_PRIVATE(promise, promiseResultSymbol, value);
+    PromiseSet(promise, status, value);
   }
 }