A derivation of the Hackage package "foo" is called "haskell-foo" if it is a
library, but only "foo" if it is an executable (without a library). This
distinction used to be fine when Haskell packages where visible to operations
like "nix-env -qa" or "nix-env -i", but after our switch to Haskell NG it has
no more purpose. Consequently, this patch removes the name prefix from all
Haskell packages -- every Haskell package is now called exactly like it's
called on Hackage.
Closes https://github.com/NixOS/nixpkgs/pull/9538.
4a8797d827