Make heap serialization nondestructive.

src/objects-inl.h

Index: src/objects-inl.h
===================================================================
--- src/objects-inl.h	(revision 3358)
+++ src/objects-inl.h	(working copy)
@@ -916,25 +916,6 @@
 }
 
 
-bool MapWord::IsSerializationAddress() {
-  return HAS_SMI_TAG(reinterpret_cast<Object*>(value_));
-}
-
-
-MapWord MapWord::FromSerializationAddress(int raw) {
-  // When the map word is being used as a serialization address we Smi-encode
-  // the serialization address (which is always a smallish positive integer).
-  return MapWord(reinterpret_cast<uintptr_t>(Smi::FromInt(raw)));
-}
-
-
-int MapWord::ToSerializationAddress() {
-  // When the map word is being used as a serialization address we treat the
-  // map word as a Smi and get the small integer that it encodes.
-  return reinterpret_cast<Smi*>(value_)->value();
-}
-
-
 bool MapWord::IsMarked() {
   return (value_ & kMarkingMask) == 0;
 }