This is the result of running the command:
$ find . -name '*.idr' -type f -exec sed -i -E 's/\s+$//' {} +
I confirmed before running it that this would not affect any markdown
formatting in documentation comments.
This is part of what we used to have in Enum but I think it's better to
separate the two. Added implementations for Nat, and anything in
Integral/Ord/Neg, so that we get range syntax (at least when its
implemeted) for the most useful cases.
