feat(3p/lisp/npg): build using buildLisp

Change-Id: I9f987dc25d77a829cc0716cbe4cb1b91c36de861
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3269
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>

third_party/lisp/npg/.skip-subtree

@@ -0,0 +1 @@
+prevent readTree from creating entries for subdirs that don't contain an .nix files

third_party/lisp/npg/OWNERS

@@ -0,0 +1,3 @@
+inherited: true
+owners:
+  - sterni

third_party/lisp/npg/README

@@ -3,6 +3,13 @@
 			   for Common Lisp
 
 	 Copyright (C) 2003-2006, 2010 by Walter C. Pelissero
+	 Copyright (C) 2021 by the TVL Authors
+
+Vendored into depot as it is a dependency of mime4cl and upstream has
+become inactive. Upstream and depot version may diverge.
+
+Upstream Website: http://wcp.sdf-eu.org/software/#npg
+Vendored Tarball: http://wcp.sdf-eu.org/software/npg-20150517T144652.tbz
 
 This library is  free software; you can redistribute  it and/or modify
 it  under  the terms  of  the GNU  Lesser  General  Public License  as
@@ -36,6 +43,6 @@ though.
 
 Multiple concurrent parsers are supported.
 
-To compile, an ASDF file is provided.
+To compile, an ASDF and nix file are provided.
 
 See the examples directory for clues on how to use it.

third_party/lisp/npg/default.nix

@@ -0,0 +1,14 @@
+# Copyright (C) 2021 by the TVL Authors
+# SPDX-License-Identifier: LGPL-2.1-or-later
+{ depot, pkgs, ... }:
+
+depot.nix.buildLisp.library {
+  name = "npg";
+
+  srcs = [
+    ./src/package.lisp
+    ./src/common.lisp
+    ./src/define.lisp
+    ./src/parser.lisp
+  ];
+}