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/compilers/ghc/7.10.1.nix

@@ -0,0 +1,51 @@
+{ stdenv, fetchurl, ghc, perl, gmp, ncurses }:
+
+let
+
+  buildMK = ''
+    libraries/integer-gmp_CONFIGURE_OPTS += --configure-option=--with-gmp-libraries="${gmp}/lib"
+    libraries/integer-gmp_CONFIGURE_OPTS += --configure-option=--with-gmp-includes="${gmp}/include"
+    libraries/terminfo_CONFIGURE_OPTS += --configure-option=--with-curses-includes="${ncurses}/include"
+    libraries/terminfo_CONFIGURE_OPTS += --configure-option=--with-curses-libraries="${ncurses}/lib"
+    DYNAMIC_BY_DEFAULT = NO
+  '';
+
+in
+
+stdenv.mkDerivation rec {
+  version = "7.10.0.20141222";
+  name = "ghc-${version}";
+
+  src = fetchurl {
+    url = "https://downloads.haskell.org/~ghc/7.10.1-rc1/ghc-7.10.0.20141222-src.tar.xz";
+    sha256 = "0nncvvwksqqz1d991jbag3b4174i275nn0psadriq5hi3px11dkl";
+  };
+
+  buildInputs = [ ghc perl ];
+
+  preConfigure = ''
+    echo >mk/build.mk "${buildMK}"
+    sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure
+  '' + stdenv.lib.optionalString (!stdenv.isDarwin) ''
+    export NIX_LDFLAGS="$NIX_LDFLAGS -rpath $out/lib/ghc-${version}"
+  '';
+
+  configureFlags = [
+    "--with-gcc=${stdenv.cc}/bin/cc"
+    "--with-gmp-includes=${gmp}/include" "--with-gmp-libraries=${gmp}/lib"
+  ];
+
+  enableParallelBuilding = true;
+
+  # required, because otherwise all symbols from HSffi.o are stripped, and
+  # that in turn causes GHCi to abort
+  stripDebugFlags = [ "-S" "--keep-file-symbols" ];
+
+  meta = {
+    homepage = "http://haskell.org/ghc";
+    description = "The Glasgow Haskell Compiler";
+    maintainers = with stdenv.lib.maintainers; [ marcweber andres simons ];
+    inherit (ghc.meta) license platforms;
+  };
+
+}

pkgs/development/compilers/ghc/head.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, ghc, perl, gmp, ncurses, happy, alex }:
+{ stdenv, fetchurl, ghc, perl, gmp, ncurses }:
 
 let
 
@@ -13,12 +13,12 @@ let
 in
 
 stdenv.mkDerivation rec {
-  version = "7.10.0.20141222";
+  version = "7.11.20150118";
   name = "ghc-${version}";
 
   src = fetchurl {
-    url = "https://downloads.haskell.org/~ghc/7.10.1-rc1/ghc-7.10.0.20141222-src.tar.xz";
-    sha256 = "0nncvvwksqqz1d991jbag3b4174i275nn0psadriq5hi3px11dkl";
+    url = "http://deb.haskell.org/dailies/2015-01-18/ghc_7.11.20150118.orig.tar.bz2";
+    sha256 = "1zy960q2faq03camq2n4834bd748vkc15h83bapswc68dqncqj20";
   };
 
   buildInputs = [ ghc perl ];