20.7
```
SELECT indexOf(['a', 'b', 'c'], toLowCardinality('a'))

┌─indexOf(['a', 'b', 'c'], toLowCardinality('a'))─┐
│                                               1 │
└─────────────────────────────────────────────────┘
```

20.8
```
SELECT indexOf(['a', 'b', 'c'], toLowCardinality('a'))


Received exception from server (version 20.8.3):
Code: 43. DB::Exception: Received from localhost:9000. DB::Exception: Types of array and 2nd argument of function "indexOf" must be identical up to nullability, cardinality, numeric types, or Enum and numeric type. Passed: Array(String) and LowCardinality(String).. 
```

https://github.com/ClickHouse/ClickHouse/pull/12550

/cc @myrrc 

const IColumn & item_arg = *columns[arguments[1]].column;
        auto col_res = ResultColumnType::create();
        auto [null_map_data, null_map_item] = getNullMaps(columns, arguments);
        if (item_arg.onlyNull())
            Impl::Null<ConcreteAction>::process(
                col->getOffsets(),
                col_res->getData(),
                null_map_data);
        else if (isColumnConst(item_arg))
            Impl::Main<ConcreteAction, true>::vector(
                col_nested,
                col->getOffsets(),
                typeid_cast<const ColumnConst &>(item_arg).getDataColumn(),
                col_res->getData(), 
                null_map_data,
                nullptr);
        else
            Impl::Main<ConcreteAction>::vector(
                col_nested,
                col->getOffsets(),
                item_arg,
                col_res->getData(),
                null_map_data,
                null_map_item);
        columns[result].column = std::move(col_res);
        return true;
    }
};
}