mingw-w64-pthreads: Create based on mingw-w64.

The winpthreads library is part of the same source package, so let's
just override the name and the source directory.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>

pkgs/os-specific/windows/mingw-w64/default.nix

@@ -1,4 +1,7 @@
-{stdenv, fetchurl, binutilsCross ? null, gccCross ? null, onlyHeaders ? false}:
+{ stdenv, fetchurl, binutilsCross ? null, gccCross ? null
+, onlyHeaders ? false
+, onlyPthreads ? false
+}:
 
 let
   name = "mingw-w64-3.1.0";
@@ -17,6 +20,11 @@ stdenv.mkDerivation (rec {
     cd mingw-w64-headers
   '';
   configureFlags = "--without-crt --host=x86_64-w64-mingw32";
+} else if onlyPthreads then {
+  name = name + "-pthreads";
+  preConfigure = ''
+    cd mingw-w64-libraries/winpthreads
+  '';
 } else {
   buildInputs = [ gccCross binutilsCross ];
 

pkgs/top-level/all-packages.nix

@@ -7191,6 +7191,10 @@ let
       onlyHeaders = true;
     };
 
+    mingw_w64_pthreads = callPackage ../os-specific/windows/mingw-w64 {
+      onlyPthreads = true;
+    };
+
     pthreads = callPackage ../os-specific/windows/pthread-w32 {
       mingw_headers = mingw_headers3;
     };