Trying to keep both up to date - apologies if I'm missed anyone. I got
the list from the git logs, but feel free to edit yourself in or out as
you prefer.
Data types with one constructor, that has one unerased argument, are
translated to that argument for runtime. This doesn't have a huge effect
on its own, but doing this will expose other optimisations later (e.g.
increasing effect of inlining).
