ghc: add alpha-1 pre-release for version 8.8.1

The patches for https://phabricator.haskell.org/D5123 and
https://github.com/haskell/haddock/issues/900 no longer
apply and have been dropped.

pkgs/development/haskell-modules/configuration-ghc-8.8.x.nix

@@ -0,0 +1,44 @@
+{ pkgs, haskellLib }:
+
+with haskellLib;
+
+self: super: {
+
+  # This compiler version needs llvm 7.x.
+  llvmPackages = pkgs.llvmPackages_7;
+
+  # Disable GHC 8.8.x core libraries.
+  array = null;
+  base = null;
+  binary = null;
+  bytestring = null;
+  Cabal = null;
+  containers = null;
+  deepseq = null;
+  directory = null;
+  filepath = null;
+  ghc-boot = null;
+  ghc-boot-th = null;
+  ghc-compact = null;
+  ghc-heap = null;
+  ghc-prim = null;
+  ghci = null;
+  haskeline = null;
+  hpc = null;
+  integer-gmp = null;
+  libiserv = null;
+  mtl = null;
+  parsec = null;
+  pretty = null;
+  process = null;
+  rts = null;
+  stm = null;
+  template-haskell = null;
+  terminfo = null;
+  text = null;
+  time = null;
+  transformers = null;
+  unix = null;
+  xhtml = null;
+
+}