[promises] reset callbacks once the promise is resolved

src/runtime/runtime-promise.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 #include "src/runtime/runtime-utils.h"
 
 #include "src/debug/debug.h"
 #include "src/elements.h"
 #include "src/promise-utils.h"
 
 namespace v8 {
@@ skipping 76 matching lines @@
       debug_name = accessor->Get(array, 1);
     }
   }
   Handle<PromiseReactionJobInfo> info =
       isolate->factory()->NewPromiseReactionJobInfo(value, tasks, deferred,
                                                     debug_id, debug_name,
                                                     isolate->native_context());
   isolate->EnqueueMicrotask(info);
 }
 
-void PromiseSet(Handle<JSPromise> promise, int status, Handle<Object> result) {
+void PromiseSet(Isolate* isolate, Handle<JSPromise> promise, int status,
+                Handle<Object> result) {
   promise->set_status(status);
   promise->set_result(*result);
-  // TODO(gsathya): reset reactions?
+  promise->set_deferred(isolate->heap()->undefined_value());
+  promise->set_fulfill_reactions(isolate->heap()->undefined_value());
+  promise->set_reject_reactions(isolate->heap()->undefined_value());
 }
 
 void PromiseFulfill(Isolate* isolate, Handle<JSPromise> promise,
                     Handle<Smi> status, Handle<Object> value) {
   // Check if there are any callbacks.
   if (!promise->deferred()->IsUndefined(isolate)) {
     Handle<Object> tasks((status->value() == kPromiseFulfilled)
                              ? promise->fulfill_reactions()
                              : promise->reject_reactions(),
                          isolate);
     Handle<Object> deferred(promise->deferred(), isolate);
     EnqueuePromiseReactionJob(isolate, value, tasks, deferred, status);
   }
 
-  PromiseSet(promise, status->value(), value);
+  PromiseSet(isolate, promise, status->value(), value);
 }
 
 }  // namespace
 
 RUNTIME_FUNCTION(Runtime_PromiseReject) {
   DCHECK(args.length() == 3);
   HandleScope scope(isolate);
   CONVERT_ARG_HANDLE_CHECKED(JSPromise, promise, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, reason, 1);
   CONVERT_BOOLEAN_ARG_CHECKED(debug_event, 2);
@@ skipping 141 matching lines @@
     return *reject_reactions;
   }
 
   DCHECK(reject_reactions->IsFixedArray());
   return *isolate->factory()->NewJSArrayWithElements(
       Handle<FixedArray>::cast(reject_reactions));
 }
 
 }  // namespace internal
 }  // namespace v8