Is there unused code in GHC source?

[Jan Stolarek]

Dear devs,

I'm trying to dig into GHC code and one thing is wondering me. Does the source contain old 
fragments of code that are not used anymore? Well, for such a big project the answer will 
probably be 'yes', but I'm wondering what the scale of this might be. I thought that such 
leftovers could be a bit misleading and I want to know if I should stay alert :)

Janek