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

src/factory.h

Index: src/factory.h
diff --git a/src/factory.h b/src/factory.h
index 24b490c3443961828d9f4529d34013acd937be36..74d9513e0dd32dac57011346b848b32d30ca40ea 100644
--- a/src/factory.h
+++ b/src/factory.h
@@ -609,11 +609,8 @@ class Factory FINAL {
 
   // 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);