Report promise reject with no handler (behind a flag).

src/factory.h

 // Copyright 2014 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.
 
 #ifndef V8_FACTORY_H_
 #define V8_FACTORY_H_
 
 #include "src/isolate.h"
 
 namespace v8 {
@@ skipping 591 matching lines @@
       Handle<Code> code, Handle<ScopeInfo> scope_info,
       Handle<TypeFeedbackVector> feedback_vector);
   Handle<SharedFunctionInfo> NewSharedFunctionInfo(Handle<String> name,
                                                    MaybeHandle<Code> code);
 
   // Allocate a new type feedback vector
   Handle<TypeFeedbackVector> NewTypeFeedbackVector(int slot_count);
 
   // Allocates a new JSMessageObject object.
   Handle<JSMessageObject> NewJSMessageObject(
-      Handle<String> type,
-      Handle<JSArray> arguments,
-      int start_position,
-      int end_position,
-      Handle<Object> script,
+      Handle<String> type, Handle<JSArray> arguments, Handle<Object> promise,
+      int start_position, int end_position, Handle<Object> script,
       Handle<Object> stack_frames);
 
   Handle<DebugInfo> NewDebugInfo(Handle<SharedFunctionInfo> shared);
 
   // Return a map using the map cache in the native context.
   // The key the an ordered set of property names.
   Handle<Map> ObjectLiteralMapFromCache(Handle<Context> context,
                                         Handle<FixedArray> keys);
 
   // Creates a new FixedArray that holds the data associated with the
@@ skipping 73 matching lines @@
   // Reinitialize a JSProxy into an (empty) JS object of respective type and
   // size, but keeping the original prototype.  The receiver must have at least
   // the size of the new object.  The object is reinitialized and behaves as an
   // object that has been freshly allocated.
   void ReinitializeJSProxy(Handle<JSProxy> proxy, InstanceType type, int size);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_FACTORY_H_