Reapply descriptor array sharing.

src/objects-debug.cc

 // 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 883 matching lines @@
          number_of_fast_used_elements_, number_of_fast_unused_elements_);
 
   PrintF("    - slow elements (#%d): %d (used) %d (unused)\n",
          number_of_objects_ - number_of_objects_with_fast_elements_,
          number_of_slow_used_elements_, number_of_slow_unused_elements_);
 
   PrintF("\n");
 }
 
 
-bool DescriptorArray::IsSortedNoDuplicates() {
+bool DescriptorArray::IsSortedNoDuplicates(int valid_entries) {
+  if (valid_entries == -1) valid_entries = number_of_descriptors();
   String* current_key = NULL;
   uint32_t current = 0;
-  for (int i = 0; i < number_of_descriptors(); i++) {
+  for (int i = 0; i < valid_entries; i++) {
     String* key = GetSortedKey(i);
     if (key == current_key) {
       PrintDescriptors();
       return false;
     }
     current_key = key;
     uint32_t hash = GetSortedKey(i)->Hash();
     if (hash < current) {
       PrintDescriptors();
       return false;
     }
     current = hash;
   }
   return true;
 }
 
 
-bool TransitionArray::IsSortedNoDuplicates() {
+bool TransitionArray::IsSortedNoDuplicates(int valid_entries) {
+  ASSERT(valid_entries == -1);
   String* current_key = NULL;
   uint32_t current = 0;
   for (int i = 0; i < number_of_transitions(); i++) {
     String* key = GetSortedKey(i);
     if (key == current_key) {
       PrintTransitions();
       return false;
     }
     current_key = key;
     uint32_t hash = GetSortedKey(i)->Hash();
@@ skipping 77 matching lines @@
   FixedArray* proto_transitions = GetPrototypeTransitions();
   MemsetPointer(proto_transitions->data_start(),
                 GetHeap()->the_hole_value(),
                 proto_transitions->length());
 }
 
 
 #endif  // DEBUG
 
 } }  // namespace v8::internal