**Describe the bug**

-2147483648 is the minimum integer representable with Int32, but ``toInt32OrNull('-2147483648')`` returns ``NULL``. On the other hand ``toInt32('-2147483648')`` correctly returns ``-2147483648``.

**Does it reproduce on recent release?**

Yes. It happens on 21.7.5.29-stable

**How to reproduce**

```
SELECT
    toInt32('-2147483648'),
    toInt32OrNull('-2147483648')

Query id: 94f4e069-6c0e-44d9-8e94-7ee83b90a529

┌─toInt32('-2147483648')─┬─toInt32OrNull('-2147483648')─┐
│            -2147483648 │                         ᴺᵁᴸᴸ │
└────────────────────────┴──────────────────────────────┘
```

**Expected behavior**

``toInt32('-2147483648')`` and ``toInt32OrNull('-2147483648')`` should both return ``-2147483648``.

}
        ++buf.position();
    }
end:
    if (has_sign && !has_number)
    {
        if constexpr (throw_exception)
            throw ParsingException(
                "Cannot parse number with a sign character but without any numeric character", ErrorCodes::CANNOT_PARSE_NUMBER);
        else
            return ReturnType(false);
    }
    x = res;
    if constexpr (is_signed_v<T>)
    {
        if (negative)
        {
            if constexpr (check_overflow == ReadIntTextCheckOverflow::CHECK_OVERFLOW)
            {
                if (common::mulOverflow<T>(x, -1, x))
                    return ReturnType(false);
            }
            else
                x = -res;
        }
    }
    return ReturnType(true);
}
template <ReadIntTextCheckOverflow check_overflow = ReadIntTextCheckOverflow::DO_NOT_CHECK_OVERFLOW, typename T>
void readIntText(T & x, ReadBuffer & buf)