Use patching for Expando so the implementation-specific files are not needed in the SDK.

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index ca07985df0bcc4a5af41cf559d1332db10185d7a..3f8cae887acce57d73cdafaadcba2556583f5854 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -629,6 +629,12 @@ RawError* Object::Init(Isolate* isolate) {
   RegisterClass(cls, name, core_impl_lib);
   pending_classes.Add(cls, Heap::kOld);
 
+  cls = Class::New<WeakProperty>();
+  object_store->set_weak_property_class(cls);
+  name = Symbols::_WeakProperty();
+  RegisterPrivateClass(cls, name, core_impl_lib);
+  pending_classes.Add(cls, Heap::kOld);

[Mads Ager (google), 2012/08/24 11:15:23]

Carl, this reflects the move of the class from core to coreimpl. I added the
addition to pending_classes just to keep it consistent with the above. Is that
the right thing to do or should I leave out the addition to pending_classes?

[cshapiro, 2012/08/25 03:18:29]

I believe you have done the right thing.  

When something goes wrong in this function, you tend to find out pretty quickly.
 If you have run all of the unit tests and they have passed, I think you can be
confident that this change is okay.

+
   // Initialize the base interfaces used by the core VM classes.
   const Script& script = Script::Handle(Bootstrap::LoadCoreScript(false));
 
@@ -746,11 +752,6 @@ RawError* Object::Init(Isolate* isolate) {
   name = Symbols::_ExternalFloat64Array();
   RegisterPrivateClass(cls, name, core_lib);
 
-  cls = Class::New<WeakProperty>();
-  object_store->set_weak_property_class(cls);
-  name = Symbols::_WeakProperty();
-  RegisterPrivateClass(cls, name, core_lib);
-
   // Set the super type of class Stacktrace to Object type so that the
   // 'toString' method is implemented.
   cls = object_store->stacktrace_class();