Allow embedder to set promise internal field count

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index ffef57c44e62a51fdd658f82e12d1a4eb9b1f1da..51874d52cd380b5113b26a2166840e7de79909f4 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -2106,9 +2106,9 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
   {  // -- P r o m i s e
     Handle<JSObject> prototype =
         factory->NewJSObject(isolate->object_function(), TENURED);
-    Handle<JSFunction> promise_fun =
-        InstallFunction(global, "Promise", JS_PROMISE_TYPE, JSPromise::kSize,
-                        prototype, Builtins::kPromiseConstructor);
+    Handle<JSFunction> promise_fun = InstallFunction(
+        global, "Promise", JS_PROMISE_TYPE, JSPromise::kSizeWithEmbedderFields,
+        prototype, Builtins::kPromiseConstructor);
     InstallWithIntrinsicDefaultProto(isolate, promise_fun,
                                      Context::PROMISE_FUNCTION_INDEX);