xorg.xdm: add libxcrypt to buildInputs

pkgs/servers/x11/xorg/overrides.nix

@@ -4,7 +4,7 @@
   freetype, tradcpp, fontconfig, meson, ninja, ed, fontforge,
   libGL, spice-protocol, zlib, libGLU, dbus, libunwind, libdrm,
   mesa, udev, bootstrap_cmds, bison, flex, clangStdenv, autoreconfHook,
-  mcpp, libepoxy, openssl, pkg-config, llvm, libxslt,
+  mcpp, libepoxy, openssl, pkg-config, llvm, libxslt, libxcrypt,
   ApplicationServices, Carbon, Cocoa, Xplugin
 }:
 
@@ -152,6 +152,10 @@ self: super:
     '';
   });
 
+  xdm = super.xdm.overrideAttrs (attrs: {
+    buildInputs = attrs.buildInputs ++ [ libxcrypt ];
+  });
+
   # Propagate some build inputs because of header file dependencies.
   # Note: most of these are in Requires.private, so maybe builder.sh
   # should propagate them automatically.