[runtime] Use PropertyKind/PropertyLocation instead of PropertyType.

src/json-stringifier.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/json-stringifier.h"
 
 #include "src/conversions.h"
 #include "src/lookup.h"
 #include "src/messages.h"
 #include "src/objects-inl.h"
@@ skipping 516 matching lines @@
     Indent();
     bool comma = false;
     for (int i = 0; i < map->NumberOfOwnDescriptors(); i++) {
       Handle<Name> name(map->instance_descriptors()->GetKey(i), isolate_);
       // TODO(rossberg): Should this throw?
       if (!name->IsString()) continue;
       Handle<String> key = Handle<String>::cast(name);
       PropertyDetails details = map->instance_descriptors()->GetDetails(i);
       if (details.IsDontEnum()) continue;
       Handle<Object> property;
-      if (details.type() == DATA && *map == js_obj->map()) {
+      if (details.location() == kField && *map == js_obj->map()) {
+        DCHECK_EQ(kData, details.kind());
         FieldIndex field_index = FieldIndex::ForDescriptor(*map, i);
         property = JSObject::FastPropertyAt(js_obj, details.representation(),
                                             field_index);
       } else {
         ASSIGN_RETURN_ON_EXCEPTION_VALUE(
             isolate_, property, Object::GetPropertyOrElement(js_obj, key),
             EXCEPTION);
       }
       Result result = SerializeProperty(property, comma, key);
       if (!comma && result == SUCCESS) comma = true;
@@ skipping 165 matching lines @@
     if (object->IsOneByteRepresentationUnderneath()) {
       SerializeString_<uint8_t, uc16>(object);
     } else {
       SerializeString_<uc16, uc16>(object);
     }
   }
 }
 
 }  // namespace internal
 }  // namespace v8