Fix Harmony sets and maps to allow null as key.

src/heap.cc

 // Copyright 2011 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 521 matching lines @@
 
 #ifdef DEBUG
 // Helper class for verifying the symbol table.
 class SymbolTableVerifier : public ObjectVisitor {
  public:
   void VisitPointers(Object** start, Object** end) {
     // Visit all HeapObject pointers in [start, end).
     for (Object** p = start; p < end; p++) {
       if ((*p)->IsHeapObject()) {
         // Check that the symbol is actually a symbol.
-        ASSERT((*p)->IsNull() || (*p)->IsUndefined() || (*p)->IsSymbol());
+        ASSERT((*p)->IsTheHole() || (*p)->IsUndefined() || (*p)->IsSymbol());
       }
     }
   }
 };
 #endif  // DEBUG
 
 
 static void VerifySymbolTable() {
 #ifdef DEBUG
   SymbolTableVerifier verifier;
@@ skipping 5782 matching lines @@
       delete caches_[i];
       caches_[i] = NULL;
     }
   }
 }
 
 
 void ExternalStringTable::CleanUp() {
   int last = 0;
   for (int i = 0; i < new_space_strings_.length(); ++i) {
-    if (new_space_strings_[i] == heap_->raw_unchecked_null_value()) continue;
+    if (new_space_strings_[i] == heap_->raw_unchecked_the_hole_value()) {
+      continue;
+    }
     if (heap_->InNewSpace(new_space_strings_[i])) {
       new_space_strings_[last++] = new_space_strings_[i];
     } else {
       old_space_strings_.Add(new_space_strings_[i]);
     }
   }
   new_space_strings_.Rewind(last);
   last = 0;
   for (int i = 0; i < old_space_strings_.length(); ++i) {
-    if (old_space_strings_[i] == heap_->raw_unchecked_null_value()) continue;
+    if (old_space_strings_[i] == heap_->raw_unchecked_the_hole_value()) {
+      continue;
+    }
     ASSERT(!heap_->InNewSpace(old_space_strings_[i]));
     old_space_strings_[last++] = old_space_strings_[i];
   }
   old_space_strings_.Rewind(last);
   if (FLAG_verify_heap) {
     Verify();
   }
 }
 
 
@@ skipping 45 matching lines @@
   isolate_->heap()->store_buffer()->Compact();
   isolate_->heap()->store_buffer()->Filter(MemoryChunk::ABOUT_TO_BE_FREED);
   for (chunk = chunks_queued_for_free_; chunk != NULL; chunk = next) {
     next = chunk->next_chunk();
     isolate_->memory_allocator()->Free(chunk);
   }
   chunks_queued_for_free_ = NULL;
 }
 
 } }  // namespace v8::internal