Add a package set for GHC 7.10.1-rc1 and bump GHC HEAD to 7.11.x.

Fixes https://github.com/NixOS/nixpkgs/issues/5836.

pkgs/development/haskell-modules/configuration-ghc-7.10.x.nix

@@ -4,7 +4,7 @@ with import ./lib.nix { inherit pkgs; };
 
 self: super: {
 
-  # Disable GHC 7.9.x core libraries.
+  # Disable GHC 7.10.x core libraries.
   array = null;
   base = null;
   binary = null;

pkgs/development/haskell-modules/configuration-ghc-head.nix

@@ -0,0 +1,85 @@
+{ pkgs }:
+
+with import ./lib.nix { inherit pkgs; };
+
+self: super: {
+
+  # Disable GHC 7.11.x core libraries.
+  array = null;
+  base = null;
+  binary = null;
+  bin-package-db = null;
+  bytestring = null;
+  Cabal = null;
+  containers = null;
+  deepseq = null;
+  directory = null;
+  filepath = null;
+  ghc-prim = null;
+  haskeline = null;
+  hoopl = null;
+  hpc = null;
+  integer-gmp = null;
+  pretty = null;
+  process = null;
+  rts = null;
+  template-haskell = null;
+  terminfo = null;
+  time = null;
+  transformers = null;
+  unix = null;
+  xhtml = null;
+
+  # We have Cabal 1.22.x.
+  jailbreak-cabal = super.jailbreak-cabal.override { Cabal = null; };
+
+  # GHC 7.10.x's Haddock binary cannot generate hoogle files.
+  # https://ghc.haskell.org/trac/ghc/ticket/9921
+  mkDerivation = drv: super.mkDerivation (drv // { doHoogle = false; });
+
+  # haddock: No input file(s).
+  nats = dontHaddock super.nats;
+
+  # These used to be core packages in GHC 7.8.x.
+  old-locale = self.old-locale_1_0_0_7;
+  old-time = self.old-time_1_1_0_3;
+
+  # We have transformers 4.x
+  mtl = self.mtl_2_2_1;
+  transformers-compat = disableCabalFlag super.transformers-compat "three";
+
+  # We have time 1.5
+  aeson = disableCabalFlag super.aeson "old-locale";
+
+  # Setup: At least the following dependencies are missing: base <4.8
+  hspec-expectations = overrideCabal super.hspec-expectations (drv: {
+    patchPhase = "sed -i -e 's|base < 4.8|base|' hspec-expectations.cabal";
+  });
+  utf8-string = overrideCabal super.utf8-string (drv: {
+    patchPhase = "sed -i -e 's|base >= 3 && < 4.8|base|' utf8-string.cabal";
+  });
+
+  # bos/attoparsec#92
+  attoparsec = dontCheck super.attoparsec;
+
+  # test suite hangs silently for at least 10 minutes
+  split = dontCheck super.split;
+
+  # Test suite fails with some (seemingly harmless) error.
+  # https://code.google.com/p/scrapyourboilerplate/issues/detail?id=24
+  syb = dontCheck super.syb;
+
+  # Test suite has stricter version bounds
+  retry = dontCheck super.retry;
+
+  # Test suite fails with time >= 1.5
+  http-date = dontCheck super.http-date;
+
+  # Version 1.19.5 fails its test suite.
+  happy = dontCheck super.happy;
+
+  # Test suite hangs silently without consuming any CPU.
+  # https://github.com/ndmitchell/extra/issues/4
+  extra = dontCheck super.extra;
+
+}