Revert "Handlify JSObject::MigrateInstance and friends."

src/hydrogen.cc

 // Copyright 2013 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 4088 matching lines @@
 
 
 // Determines whether the given array or object literal boilerplate satisfies
 // all limits to be considered for fast deep-copying and computes the total
 // size of all objects that are part of the graph.
 static bool IsFastLiteral(Handle<JSObject> boilerplate,
                           int max_depth,
                           int* max_properties) {
   if (boilerplate->map()->is_deprecated()) {
     Handle<Object> result = JSObject::TryMigrateInstance(boilerplate);
-    if (result.is_null()) return false;
+    if (result->IsSmi()) return false;
   }
 
   ASSERT(max_depth >= 0 && *max_properties >= 0);
   if (max_depth == 0) return false;
 
   Isolate* isolate = boilerplate->GetIsolate();
   Handle<FixedArrayBase> elements(boilerplate->elements());
   if (elements->length() > 0 &&
       elements->map() != isolate->heap()->fixed_cow_array_map()) {
     if (boilerplate->HasFastObjectElements()) {
@@ skipping 5654 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal