[heap] Avoid overzealous inclusion of heap internal headers.

src/messages.cc

 // Copyright 2011 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.
 
 #include "src/v8.h"
 
 #include "src/api.h"
 #include "src/execution.h"
-#include "src/heap/spaces-inl.h"
 #include "src/messages.h"
 #include "src/string-builder.h"
 
 namespace v8 {
 namespace internal {
 
 
 // If no message listeners have been registered this one is called
 // by default.
 void MessageHandler::DefaultMessageReport(Isolate* isolate,
@@ skipping 343 matching lines @@
       }
     } else {
       builder.AppendCharacter(*c);
     }
   }
 
   return builder.Finish();
 }
 }  // namespace internal
 }  // namespace v8