More hs-boot file troubles

[Donald Bruce Stewart]

simonpj:
> GHC should not crash.
> 
> But, as a separate matter, hs-boot files are always to be regarded
> with suspicion.  Why do you need Num.hs-boot.  I think it's because
> GHC.Num imports GHC.Show which imports GHC.List which imports

Yes, exactly this. Just trying to break that loop.

> Data.List.Stream.  But that's stupid. Show only uses a couple of
> functions from List, and it's a Bad Idea to make a great big module
> loop for the sake of foldr1, or whatever.  I urge you to un-loop-ify
> your code.

Ok. That's a good idea. Identifying the best way to break these
multi-module loops is tricky!

> Meanwhile I'll find out why it's crashing anyway

-- Don