bit sets in IntSet vs. Integer

[Henning Thielemann]

On Sun, 19 Jun 2016, David Feuer wrote:

> I know that Sergei Lebedev did quite a bit of work (for the bitset 
> package) optimizing certain Integer bit operations. That code doesn't 
> work with the new Integer, but it can probably be adapted.

>From a quick look, it simply gives names of set operation to existing 
Data.Bits methods on Integer. I cannot see much custom optimizations.