64bit literal integer is not available on macOS High Sierra

```
Io> 0x12345678 asHex
==> 12345678
Io> 0x1234567890 asHex
==> 34567890
```
when literal integer more than 4 bytes, the high bits will be truncated (e.g. the `12` of `0x1234567890`), this problem does still exist in latest release (2017.09.06 )
