VM: Field::IsConsistentWith should check unboxing state of the field.

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/cpu.h"
@@ skipping 7691 matching lines @@
   ASSERT(IsOriginal());
   FieldDependentArray a(*this);
   a.DisableCode();
 }
 
 
 bool Field::IsConsistentWith(const Field& other) const {
   return (raw_ptr()->guarded_cid_ == other.raw_ptr()->guarded_cid_) &&
          (raw_ptr()->is_nullable_ == other.raw_ptr()->is_nullable_) &&
          (raw_ptr()->guarded_list_length_ ==
-             other.raw_ptr()->guarded_list_length_);
+             other.raw_ptr()->guarded_list_length_) &&
+         (is_unboxing_candidate() == other.is_unboxing_candidate());
 }
 
 
 bool Field::IsUninitialized() const {
   const Instance& value = Instance::Handle(raw_ptr()->value_.static_value_);
   ASSERT(value.raw() != Object::transition_sentinel().raw());
   return value.raw() == Object::sentinel().raw();
 }
 
 
@@ skipping 14887 matching lines @@
   return UserTag::null();
 }
 
 
 const char* UserTag::ToCString() const {
   const String& tag_label = String::Handle(label());
   return tag_label.ToCString();
 }
 
 }  // namespace dart