Introduce FieldIndex to unify and abstract property/field offset

src/heap-snapshot-generator.cc

 // Copyright 2013 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/v8.h"
 
 #include "src/heap-snapshot-generator-inl.h"
 
 #include "src/allocation-tracker.h"
 #include "src/code-stubs.h"
@@ skipping 1642 matching lines @@
                   NULL,
                   js_obj->GetInObjectPropertyOffset(index));
             } else {
               TagObject(value, "(hidden properties)");
               SetInternalReference(
                   js_obj, entry,
                   "hidden_properties", value,
                   js_obj->GetInObjectPropertyOffset(index));
             }
           } else {
-            Object* value = js_obj->RawFastPropertyAt(index);
+            FieldIndex field_index =
+                FieldIndex::ForDescriptor(js_obj->map(), i);
+            Object* value = js_obj->RawFastPropertyAt(field_index);
             if (k != heap_->hidden_string()) {
               SetPropertyReference(js_obj, entry, k, value);
             } else {
               TagObject(value, "(hidden properties)");
               SetInternalReference(js_obj, entry, "hidden_properties", value);
             }
           }
           break;
         }
         case CONSTANT:
@@ skipping 1495 matching lines @@
   writer_->AddString("\"<dummy>\"");
   for (int i = 1; i < sorted_strings.length(); ++i) {
     writer_->AddCharacter(',');
     SerializeString(sorted_strings[i]);
     if (writer_->aborted()) return;
   }
 }
 
 
 } }  // namespace v8::internal