Hackage4Nix.hs: replace the old regex-parser with the BNFC-generated one
Hackage4Nix.hs: replace the old regex-parser with the BNFC-generated one

jb55/cabal2nix,spencerjanssen/cabal2nix,bennofs/cabal2nix,dmalikov/cabal2nix,gridaphobe/cabal2nix,Fuuzetsu/cabal2nix,psibi/cabal2nix