Tag smi-constants as smi. This also fixes code that copies holes into arrays.

src/code-stubs-hydrogen.cc

 // Copyright 2012 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 652 matching lines @@
   CompareNilICStub* stub = casted_stub();
   HIfContinuation continuation;
   Handle<Map> sentinel_map(graph()->isolate()->heap()->meta_map());
   BuildCompareNil(GetParameter(0), stub->GetKind(),
                   stub->GetTypes(), sentinel_map,
                   RelocInfo::kNoPosition, &continuation);
   IfBuilder if_nil(this, &continuation);
   if_nil.Then();
   if (continuation.IsFalseReachable()) {
     if_nil.Else();
-    if_nil.Return(graph()->GetConstantSmi0());
+    if_nil.Return(graph()->GetConstant0());
   }
   if_nil.End();
   return continuation.IsTrueReachable()
-      ? graph()->GetConstantSmi1()
+      ? graph()->GetConstant1()
       : graph()->GetConstantUndefined();
 }
 
 
 Handle<Code> CompareNilICStub::GenerateCode() {
   return DoGenerateCode(this);
 }
 
 } }  // namespace v8::internal