ghc-8.0.2: Fix #44987 (#45014)

nix-env -f '<nixpkgs>' -qaP -A haskell.packages.ghc802

will run again, but the packages depending on ghc-compact will still not
build, as they have a constrain on base >= 4.10 and ghc 8.0.2 has base
4.9.1.0