Fix handling arrays with holes in JSON.stringify.

src/json-stringifier.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 395 matching lines @@
   switch (object->GetElementsKind()) {
     case FAST_SMI_ELEMENTS: {
       Handle<FixedArray> elements = Handle<FixedArray>(
           FixedArray::cast(object->elements()));
       for (int i = 0; i < length; i++) {
         if (i > 0) Append(',');
         SerializeSmi(Smi::cast(elements->get(i)));
       }
       break;
     }
-    case FAST_HOLEY_SMI_ELEMENTS: {
-      Handle<FixedArray> elements = Handle<FixedArray>(
-          FixedArray::cast(object->elements()));
-      for (int i = 0; i < length; i++) {
-        if (i > 0) Append(',');
-        if (elements->is_the_hole(i)) {
-          Append("null");
-        } else {
-          SerializeSmi(Smi::cast(elements->get(i)));
-        }
-      }
-      break;
-    }
-    case FAST_HOLEY_DOUBLE_ELEMENTS:
     case FAST_DOUBLE_ELEMENTS: {
       Handle<FixedDoubleArray> elements = Handle<FixedDoubleArray>(
           FixedDoubleArray::cast(object->elements()));
       for (int i = 0; i < length; i++) {
         if (i > 0) Append(',');
         SerializeDouble(elements->get_scalar(i));
       }
       break;
     }
-    case FAST_HOLEY_ELEMENTS:
     case FAST_ELEMENTS: {
       Handle<FixedArray> elements = Handle<FixedArray>(
           FixedArray::cast(object->elements()));
       for (int i = 0; i < length; i++) {
         if (i > 0) Append(',');
         Result result = Serialize(Handle<Object>(elements->get(i)));
         if (result == SUCCESS) continue;
         if (result == UNCHANGED) {
           Append("null");
         } else {
@@ skipping 227 matching lines @@
       SerializeString_<false, char>(flat.ToAsciiVector(), object);
     } else {
       SerializeString_<false, uc16>(flat.ToUC16Vector(), object);
     }
   }
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_JSON_STRINGIFIER_H_