"Modularizing GHC" paper

[Sylvain Henry]

Hi GHC devs,

With John Ericson and Jeffrey Young we wrote a paper about the 
modularization of GHC. It gives a global picture for the refactorings we 
have been performing (c.f. e.g. #17957) and some potential future ones.

Announce blog post: 
https://hsyl20.fr/home/posts/2022-05-03-modularizing-ghc-paper.html
Paper: https://hsyl20.fr/home/files/papers/2022-ghc-modularity.pdf
Discussion on Reddit: 
https://www.reddit.com/r/haskell/comments/uhdu4l/modularizing_ghc_paper/

We welcome any feedback, here or on reddit.

Cheers,
Sylvain