Remove obsolete stack trace string in a message object.

src/heap.cc

Index: src/heap.cc
diff --git a/src/heap.cc b/src/heap.cc
index dfe98ec080c38009871c4f2357d532e5ec8d40d1..1c05f445d37252f3f517b9d84636a64e9bc39bcf 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -3770,7 +3770,6 @@ MaybeObject* Heap::AllocateJSMessageObject(String* type,
                                            int start_position,
                                            int end_position,
                                            Object* script,
-                                           Object* stack_trace,
                                            Object* stack_frames) {
   Object* result;
   { MaybeObject* maybe_result = Allocate(message_object_map(), NEW_SPACE);
@@ -3785,7 +3784,6 @@ MaybeObject* Heap::AllocateJSMessageObject(String* type,
   message->set_start_position(start_position);
   message->set_end_position(end_position);
   message->set_script(script);
-  message->set_stack_trace(stack_trace);
   message->set_stack_frames(stack_frames);
   return result;
 }