Revert "Replace HeapNumber as doublebox with an explicit MutableHeapNumber."

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index d600b4ec25103c250d527f6914fc91895f380543..16d0acd6e3caf045cb3bc470b71f7b3b841b18fa 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -165,7 +165,6 @@ bool Object::IsHeapObject() const {
 
 
 TYPE_CHECKER(HeapNumber, HEAP_NUMBER_TYPE)
-TYPE_CHECKER(MutableHeapNumber, MUTABLE_HEAP_NUMBER_TYPE)
 TYPE_CHECKER(Symbol, SYMBOL_TYPE)
 
 
@@ -278,27 +277,10 @@ Handle<Object> Object::NewStorageFor(Isolate* isolate,
     return handle(Smi::FromInt(0), isolate);
   }
   if (!representation.IsDouble()) return object;
-  double value;
   if (object->IsUninitialized()) {
-    value = 0;
-  } else if (object->IsMutableHeapNumber()) {
-    value = HeapNumber::cast(*object)->value();
-  } else {
-    value = object->Number();
-  }
-  return isolate->factory()->NewHeapNumber(value, MUTABLE);
-}
-
-
-Handle<Object> Object::WrapForRead(Isolate* isolate,
-                                   Handle<Object> object,
-                                   Representation representation) {
-  ASSERT(!object->IsUninitialized());
-  if (!representation.IsDouble()) {
-    ASSERT(object->FitsRepresentation(representation));
-    return object;
+    return isolate->factory()->NewHeapNumber(0);
   }
-  return isolate->factory()->NewHeapNumber(HeapNumber::cast(*object)->value());
+  return isolate->factory()->NewHeapNumber(object->Number());
 }
 
 
@@ -3097,6 +3079,7 @@ CAST_ACCESSOR(FixedTypedArrayBase)
 CAST_ACCESSOR(Foreign)
 CAST_ACCESSOR(FreeSpace)
 CAST_ACCESSOR(GlobalObject)
+CAST_ACCESSOR(HeapNumber)
 CAST_ACCESSOR(HeapObject)
 CAST_ACCESSOR(JSArray)
 CAST_ACCESSOR(JSArrayBuffer)
@@ -5961,18 +5944,6 @@ ACCESSORS(JSModule, scope_info, ScopeInfo, kScopeInfoOffset)
 ACCESSORS(JSValue, value, Object, kValueOffset)
 
 
-HeapNumber* HeapNumber::cast(Object* object) {
-  SLOW_ASSERT(object->IsHeapNumber() || object->IsMutableHeapNumber());
-  return reinterpret_cast<HeapNumber*>(object);
-}
-
-
-const HeapNumber* HeapNumber::cast(const Object* object) {
-  SLOW_ASSERT(object->IsHeapNumber() || object->IsMutableHeapNumber());
-  return reinterpret_cast<const HeapNumber*>(object);
-}
-
-
 ACCESSORS(JSDate, value, Object, kValueOffset)
 ACCESSORS(JSDate, cache_stamp, Object, kCacheStampOffset)
 ACCESSORS(JSDate, year, Object, kYearOffset)