chore(3p/lisp): import npg source tarball

Used http://wcp.sdf-eu.org/software/npg-20150517T144652.tbz (sha256
42e88f6067128fbdb3a3d578371c9b0ee2a34f1d36daf80be8a520094132d828).
There's no upstream repository nor a release since 2015, so importing
seems to make a lot of sense.

Since we can't subtree making any depot-related changes in a separate CL
-- this is only the source import.

Change-Id: I64c984ca0a84b9e48c6f496577ffccce1d7bdceb
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3377
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>

third_party/lisp/npg/src/package.lisp

@@ -0,0 +1,50 @@
+;;;  package.lisp --- backtracking parser package definition
+
+;;;  Copyright (C) 2003-2006, 2009 by Walter C. Pelissero
+
+;;;  Author: Walter C. Pelissero <walter@pelissero.de>
+;;;  Project: NPG a Naive Parser Generator
+
+#+cmu (ext:file-comment "$Module: package.lisp $")
+
+;;; This library is free software; you can redistribute it and/or
+;;; modify it under the terms of the GNU Lesser General Public License
+;;; as published by the Free Software Foundation; either version 2.1
+;;; of the License, or (at your option) any later version.
+;;; This library is distributed in the hope that it will be useful,
+;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+;;; Lesser General Public License for more details.
+;;; You should have received a copy of the GNU Lesser General Public
+;;; License along with this library; if not, write to the Free
+;;; Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+;;; 02111-1307 USA
+
+(in-package :cl-user)
+
+(defpackage :naive-parser-generator
+  (:nicknames :npg)
+  (:use :common-lisp)
+  (:export
+   #:parse				; The Parser
+   #:reset-grammar
+   #:generate-grammar
+   #:print-grammar-figures
+   #:grammar-keyword-p
+   #:keyword
+   #:grammar
+   #:make-token
+   #:token-value
+   #:token-type
+   #:token-position
+   #:later-position
+   #:defrule				; to define grammars
+   #:deftoken				; to define a lexer
+   #:input-cursor-mixin
+   #:copy-input-cursor-slots
+   #:dup-input-cursor
+   #:read-next-tokens
+   #:end-of-input
+   #:? #:+ #:* #:or
+   #:$vars #:$all #:$alist
+   #:$1 #:$2 #:$3 #:$4 #:$5 #:$6 #:$7 #:$8 #:$9 #:$10))