Teach gen_snapshot how to create script snapshots if given a core snapshot to create them against.

runtime/bin/dartutils.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "bin/dartutils.h"
 
 #include "bin/crypto.h"
 #include "bin/directory.h"
 #include "bin/extensions.h"
 #include "bin/file.h"
@@ skipping 672 matching lines @@
   RETURN_IF_ERROR(url);
   Dart_Handle isolate_lib = Dart_LookupLibrary(url);
   RETURN_IF_ERROR(isolate_lib);
   url = NewString(kInternalLibURL);
   RETURN_IF_ERROR(url);
   Dart_Handle internal_lib = Dart_LookupLibrary(url);
   RETURN_IF_ERROR(internal_lib);
   Dart_Handle builtin_lib =
       Builtin::LoadAndCheckLibrary(Builtin::kBuiltinLibrary);
   RETURN_IF_ERROR(builtin_lib);
+  Builtin::SetNativeResolver(Builtin::kBuiltinLibrary);
   Dart_Handle io_lib = Builtin::LoadAndCheckLibrary(Builtin::kIOLibrary);
   RETURN_IF_ERROR(io_lib);
+  Builtin::SetNativeResolver(Builtin::kIOLibrary);
 
   // Setup the builtin library in a persistent handle attached the isolate
   // specific data as we seem to lookup and use builtin lib a lot.
   IsolateData* isolate_data =
       reinterpret_cast<IsolateData*>(Dart_CurrentIsolateData());
   ASSERT(isolate_data != NULL);
   isolate_data->set_builtin_lib(builtin_lib);
 
   // We need to ensure that all the scripts loaded so far are finalized
   // as we are about to invoke some Dart code below to setup closures.
@@ skipping 475 matching lines @@
       new CObjectString(CObject::NewString(os_error->message()));
   CObjectArray* result = new CObjectArray(CObject::NewArray(3));
   result->SetAt(0, new CObjectInt32(CObject::NewInt32(kOSError)));
   result->SetAt(1, new CObjectInt32(CObject::NewInt32(os_error->code())));
   result->SetAt(2, error_message);
   return result;
 }
 
 }  // namespace bin
 }  // namespace dart