windows: refactor

pkgs/os-specific/windows/w32api/common.nix

@@ -1,14 +0,0 @@
-{ fetchurl, xz }:
-
-rec {
-  name = "w32api-3.17-2";
-
-  src = fetchurl {
-    url = "mirror://sourceforge/mingw/MinGW/Base/w32api/w32api-3.17/${name}-mingw32-src.tar.lzma";
-    sha256 = "09rhnl6zikmdyb960im55jck0rdy5z9nlg3akx68ixn7khf3j8wb";
-  };
-
-  nativeBuildInputs = [ xz ];
-
-  meta.platforms = [ lib.systems.inspect.isMinGW ];
-}

pkgs/os-specific/windows/w32api/default.nix

@@ -1,6 +1,14 @@
-{ stdenv, callPackage }:
+{ stdenv, fetchurl, xz, lib }:
+
+stdenv.mkDerivation rec {
+  name = "w32api-3.17-2";
+
+  src = fetchurl {
+    url = "mirror://sourceforge/mingw/MinGW/Base/w32api/w32api-3.17/${name}-mingw32-src.tar.lzma";
+    sha256 = "09rhnl6zikmdyb960im55jck0rdy5z9nlg3akx68ixn7khf3j8wb";
+  };
+
+  meta.platforms = [ lib.systems.inspect.isMinGW ];
 
-stdenv.mkDerivation {
-  inherit (callPackage ./common.nix {}) name src nativeBuildInputs meta;
   dontStrip = true;
 }

pkgs/os-specific/windows/w32api/headers.nix

@@ -1,17 +0,0 @@
-{ stdenvNoCC, callPackage }:
-
-let
-  inherit (callPackage ./common.nix {}) name src meta;
-
-in stdenvNoCC.mkDerivation {
-  name = name + "-headers";
-
-  inherit src nativeBuildInputs meta;
-
-  phases = [ "unpackPhase" "installPhase" ];
-
-  installPhase = ''
-    mkdir -p $out
-    cp -R include $out
-  '';
-}