Address comments about safely casting handles.

runtime/vm/object.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 "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/bigint_operations.h"
@@ skipping 9298 matching lines @@
 
 
 bool Type::HasResolvedTypeClass() const {
   const Object& type_class = Object::Handle(raw_ptr()->type_class_);
   return !type_class.IsNull() && type_class.IsClass();
 }
 
 
 RawClass* Type::type_class() const {
   ASSERT(HasResolvedTypeClass());
+#ifdef DEBUG
+  Class& type_class = Class::Handle();
+  type_class ^= raw_ptr()->type_class_;
+  return type_class.raw();
+#else
   return reinterpret_cast<RawClass*>(raw_ptr()->type_class_);
+#endif
 }
 
 
 RawUnresolvedClass* Type::unresolved_class() const {
+  ASSERT(!HasResolvedTypeClass());
+#ifdef DEBUG
+  UnresolvedClass& unresolved_class = UnresolvedClass::Handle();
+  unresolved_class ^= raw_ptr()->type_class_;
+  ASSERT(!unresolved_class.IsNull());
+  return unresolved_class.raw();
+#else
   ASSERT(!Object::Handle(raw_ptr()->type_class_).IsNull());
   ASSERT(Object::Handle(raw_ptr()->type_class_).IsUnresolvedClass());
   return reinterpret_cast<RawUnresolvedClass*>(raw_ptr()->type_class_);
+#endif
 }
 
 
 RawString* Type::TypeClassName() const {
   if (HasResolvedTypeClass()) {
     const Class& cls = Class::Handle(type_class());
     return cls.Name();
   } else {
     const UnresolvedClass& cls = UnresolvedClass::Handle(unresolved_class());
     return cls.Name();
@@ skipping 3453 matching lines @@
   }
   return result.raw();
 }
 
 
 const char* WeakProperty::ToCString() const {
   return "_WeakProperty";
 }
 
 }  // namespace dart