| Index: src/runtime.cc
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| diff --git a/src/runtime.cc b/src/runtime.cc
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| index e8003b6731cc77740ed36596a90a59fcfe957027..a86aa409b329f731c74d2c4f4a38c4efc87e98a0 100644
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| --- a/src/runtime.cc
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| +++ b/src/runtime.cc
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| @@ -4377,6 +4377,16 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_SetProperty) {
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|  }
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|  
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|  
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| +RUNTIME_FUNCTION(MaybeObject*, Runtime_TransitionElementsKind) {
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| +  HandleScope scope(isolate);
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| +  RUNTIME_ASSERT(args.length() == 2);
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| +  CONVERT_ARG_HANDLE_CHECKED(JSArray, array, 0);
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| +  CONVERT_ARG_HANDLE_CHECKED(Map, map, 1);
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| +  JSObject::TransitionElementsKind(array, map->elements_kind());
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| +  return *array;
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| +}
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| +
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| +
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|  RUNTIME_FUNCTION(MaybeObject*, Runtime_TransitionElementsSmiToDouble) {
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|    NoHandleAllocation ha;
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|    RUNTIME_ASSERT(args.length() == 1);
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| 
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