[promisehook] Implement PromiseHook

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 0c2c76846fdc0a5e04346af92069e4f39702795b..865f999553a0f2087bc2d9987274f0f59b55a5b3 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -8247,6 +8247,10 @@ void Isolate::RemoveCallCompletedCallback(
       reinterpret_cast<CallCompletedCallback>(callback));
 }
 
+void Isolate::SetPromiseHook(PromiseHook hook) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
+  isolate->SetPromiseHook(hook);
+}
 
 void Isolate::SetPromiseRejectCallback(PromiseRejectCallback callback) {
   if (callback == NULL) return;