Use mingw-w64 for 32bit Windows builds as well.

Mingw(32) is rather poorly maintaned and has quite a lot of bugs. And
because our Windows cross builds were also poorly maintained and most of
the cross-tests were broken as well, I'm just taking this step and try
to switch to mingw-w64 for everything "cross Windows".

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

pkgs/development/libraries/pcre/default.nix

@@ -26,7 +26,7 @@ stdenv.mkDerivation rec {
     # XXX: test failure on Cygwin
     # we are running out of stack on both freeBSDs on Hydra
 
-  crossAttrs = optionalAttrs (stdenv.cross.config == "x86_64-w64-mingw32") {
+  crossAttrs = optionalAttrs (stdenv.cross.libc == "msvcrt") {
     buildInputs = [ windows.mingw_w64_pthreads.crossDrv ];
   };