Something I thought to do while refactoring #3622 but which needs to wait.

See https://stackoverflow.com/questions/59739476/deprecate-or-shadow-a-module-or-function-from-a-third-party-library#59740286

This seems to work pretty well except that it breaks stack ghci: commercialhaskell/stack#3862

So I think this is blocked on the work in #3558