title: Converting a big.Int to little-endian byte slice
body: <p>I have a big.Int and want to convert it to a little-endian byte slice. If I use <a href="https://golang.org/pkg/math/big/#Int.Bytes" rel="noreferrer">Int.Bytes</a>, I get the big-endian byte slice. </p>
  
  <p>Is there any way to get little-endian byte slice for big.Int?</p>