Do not put D8 and TEST natives into the external snapshot.

src/natives-external.cc

 // 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.
 
 #include "src/natives.h"
 
 #include "src/base/logging.h"
 #include "src/list.h"
 #include "src/list-inl.h"
 #include "src/snapshot-source-sink.h"
@@ skipping 173 matching lines @@
 void NativesCollection<type>::SetRawScriptsSource(
     Vector<const char> raw_source) {
   CHECK(false);  // Use SetNativesFromFile for this implementation.
 }
 
 
 // The compiler can't 'see' all uses of the static methods and hence
 // my chose to elide them. This we'll explicitly instantiate these.
 template class NativesCollection<CORE>;
 template class NativesCollection<EXPERIMENTAL>;
-template class NativesCollection<D8>;
-template class NativesCollection<TEST>;
 
 }  // namespace v8::internal
 }  // namespace v8