[turbofan] Use CompareNilIC for abstract equality with null/undefined.

src/ic/ic.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/ic/ic.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/arguments.h"
 #include "src/base/bits.h"
@@ skipping 2899 matching lines @@
   Code* code = NULL;
   CHECK(stub.FindCodeInCache(&code));
 
   SetTargetAtAddress(address, code, constant_pool);
 }
 
 
 Handle<Object> CompareNilIC::DoCompareNilSlow(Isolate* isolate, NilValue nil,
                                               Handle<Object> object) {
   if (object->IsNull() || object->IsUndefined()) {
-    return handle(Smi::FromInt(true), isolate);
+    return isolate->factory()->true_value();
   }
-  return handle(Smi::FromInt(object->IsUndetectableObject()), isolate);
+  return isolate->factory()->ToBoolean(object->IsUndetectableObject());
 }
 
 
 Handle<Object> CompareNilIC::CompareNil(Handle<Object> object) {
   ExtraICState extra_ic_state = target()->extra_ic_state();
 
   CompareNilICStub stub(isolate(), extra_ic_state);
 
   // Extract the current supported types from the patched IC and calculate what
   // types must be supported as a result of the miss.
@@ skipping 216 matching lines @@
     KeyedLoadICNexus nexus(vector, vector_slot);
     KeyedLoadIC ic(IC::EXTRA_CALL_FRAME, isolate, &nexus);
     ic.UpdateState(receiver, key);
     ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, ic.Load(receiver, key));
   }
 
   return *result;
 }
 }  // namespace internal
 }  // namespace v8