Put metadata fields in their owner class.

runtime/vm/class_finalizer.cc

 // Copyright (c) 2013, 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 "vm/class_finalizer.h"
 
 #include "vm/code_generator.h"
 #include "vm/flags.h"
 #include "vm/heap.h"
 #include "vm/isolate.h"
@@ skipping 2271 matching lines @@
     ASSERT(!super_class.IsNull());
     super_class.AddDirectSubclass(cls);
   }
   // A top level class is parsed eagerly so just finalize it.
   if (cls.IsTopLevel()) {
     FinalizeClass(cls);
   } else {
     // This class should not contain any fields or functions yet, because it has
     // not been compiled yet. Since 'ResolveAndFinalizeMemberTypes(cls)' has not
     // been called yet, unfinalized member types could choke the snapshotter.
-    ASSERT(Array::Handle(cls.fields()).Length() == 0);

[rmacnak, 2014/05/08 01:35:21]

This assert no longer holds because we can have metadata before the class is
fully compiled.  Put a bit in Field marking it as a metadata field and assert
only metadata fields here?

     ASSERT(Array::Handle(cls.functions()).Length() == 0);
   }
 }
 
 
 void ClassFinalizer::FinalizeClass(const Class& cls) {
   HANDLESCOPE(Isolate::Current());
   if (cls.is_finalized()) {
     return;
   }
@@ skipping 769 matching lines @@
   expected_name ^= String::New("_offset");
   ASSERT(String::EqualsIgnoringPrivateKey(name, expected_name));
   field ^= fields_array.At(2);
   ASSERT(field.Offset() == TypedDataView::length_offset());
   name ^= field.name();
   ASSERT(name.Equals("length"));
 #endif
 }
 
 }  // namespace dart