message: Use Register_*_REF for reduce operators in BuiltinRefOpResolver
diff: @@ -101,11 +101,11 @@ TfLiteRegistration* Register_LESS_EQUAL();
  TfLiteRegistration* Register_FLOOR_REF();
  TfLiteRegistration* Register_TILE();
  TfLiteRegistration* Register_NEG();
  -TfLiteRegistration* Register_SUM();
  -TfLiteRegistration* Register_REDUCE_PROD();
  -TfLiteRegistration* Register_REDUCE_MAX();
  -TfLiteRegistration* Register_REDUCE_MIN();
  -TfLiteRegistration* Register_REDUCE_ANY();
  +TfLiteRegistration* Register_SUM_REF();
  +TfLiteRegistration* Register_REDUCE_PROD_REF();
  +TfLiteRegistration* Register_REDUCE_MAX_REF();
  +TfLiteRegistration* Register_REDUCE_MIN_REF();
  +TfLiteRegistration* Register_REDUCE_ANY_REF();
  TfLiteRegistration* Register_SELECT();
  TfLiteRegistration* Register_SLICE_REF();
  TfLiteRegistration* Register_SIN();
  @@ -368,17 +368,17 @@ BuiltinRefOpResolver::BuiltinRefOpResolver() {
  AddBuiltin(BuiltinOperator_TILE, Register_TILE(),
  /* min_version = */ 1,
  /* max_version = */ 2);
  - AddBuiltin(BuiltinOperator_SUM, Register_SUM(),
  + AddBuiltin(BuiltinOperator_SUM, Register_SUM_REF(),
  /* min_version = */ 1,
  /* max_version = */ 2);
  - AddBuiltin(BuiltinOperator_REDUCE_PROD, Register_REDUCE_PROD());
  - AddBuiltin(BuiltinOperator_REDUCE_MAX, Register_REDUCE_MAX(),
  + AddBuiltin(BuiltinOperator_REDUCE_PROD, Register_REDUCE_PROD_REF());
  + AddBuiltin(BuiltinOperator_REDUCE_MAX, Register_REDUCE_MAX_REF(),
  /* min_version = */ 1,
  /* max_version = */ 3);
  - AddBuiltin(BuiltinOperator_REDUCE_MIN, Register_REDUCE_MIN(),
  + AddBuiltin(BuiltinOperator_REDUCE_MIN, Register_REDUCE_MIN_REF(),
  /* min_version = */ 1,
  /* max_version = */ 3);
  - AddBuiltin(BuiltinOperator_REDUCE_ANY, Register_REDUCE_ANY());
  + AddBuiltin(BuiltinOperator_REDUCE_ANY, Register_REDUCE_ANY_REF());
  AddBuiltin(BuiltinOperator_EXPAND_DIMS, Register_EXPAND_DIMS());
  AddBuiltin(BuiltinOperator_SPARSE_TO_DENSE, Register_SPARSE_TO_DENSE(),
  /* min_version = */ 1,
  