I added the original fast implementation in this CL https://go.dev/cl/2828 because I found it useful, clear, and efficient in tuple "less" comparisons like this:

   if cmp := strings.Compare(x.first, y.first); cmp != 0 {
       return cmp < 0
   }
   if cmp := strings.Compare(x.second, y.second); cmp != 0 {
       return cmp < 0
   }
   ...

Compared to the != then < approach, it makes only a single pass over the string data. To this day I never understood the justification for intentionally making it slower, or why the style of code above isn't reasonable.