Add a type for objects with typed properties.

src/types-inl.h

Index: src/types-inl.h
diff --git a/src/types-inl.h b/src/types-inl.h
index 762a11df303d85f6c8289d8526564233140def4d..d21c04fe8efeca64782a7a5d52d0a08b5c82e272 100644
--- a/src/types-inl.h
+++ b/src/types-inl.h
@@ -33,7 +33,8 @@ template<class Config>
 TypeImpl<Config>* TypeImpl<Config>::cast(typename Config::Base* object) {
   TypeImpl* t = static_cast<TypeImpl*>(object);
   DCHECK(t->IsBitset() || t->IsClass() || t->IsConstant() || t->IsRange() ||
-         t->IsUnion() || t->IsArray() || t->IsFunction() || t->IsContext());
+         t->IsUnion() || t->IsArray() || t->IsFunction() || t->IsObject() ||
+         t->IsContext());
   return t;
 }