Update flex from ancient 2.5.4 to the recent 2.5.39.

This work was all done by Serguey Parkhomovsky. Thanks.
Some changes from upstream:
* Removed autotools cruft/localization/texinfo manual/etc
* Kept the old manpage, as the new manpage is content-free
* Used safe string handling functions and fixed several compiler warnings
* pledge(2). Flex 2.5.39 now forks/execs its filter chains and needs proc
  exec in addition to what was previously pledged
* Removed register keyword from all variable declarations
* renamed parse.c, parse.h, scan.c, skel.c with init prefix so compiling
  flex outside of obj by accident wouldn't clobber the bootstrap files
* Minor fixes (spelling, accessing buf[strlen(buf) - 1] for zero-length
  strings in initscan.c/scan.l, etc) that were already in our tree

This is a huge change, so it's going in the tree code bomb style.
I'm not excited about the growth in complexity (like now running m4
to _post_ process lexers) but hopefully this will be a one time update
and we will now take "ownership" of the code.

1 files changed, 25 insertions, 9 deletions

diff --git a/usr.bin/lex/libmain.c b/usr.bin/lex/libmain.c
index 61cca7db456..37bc4ee1347 100644
--- a/usr.bin/lex/libmain.c
+++ b/usr.bin/lex/libmain.c
@@ -1,19 +1,35 @@
-/*	$OpenBSD: libmain.c,v 1.7 2012/12/05 23:20:25 deraadt Exp $	*/
+/*	$OpenBSD: libmain.c,v 1.8 2015/11/19 19:43:40 tedu Exp $	*/
 
 /* libmain - flex run-time support library "main" function */
 
-/* $Header: /home/cvs/src/usr.bin/lex/libmain.c,v 1.7 2012/12/05 23:20:25 deraadt Exp $ */
+/*  This file is part of flex. */
 
+/*  Redistribution and use in source and binary forms, with or without */
+/*  modification, are permitted provided that the following conditions */
+/*  are met: */
 
-int yylex(void);
-int main(int, char **);
+/*  1. Redistributions of source code must retain the above copyright */
+/*     notice, this list of conditions and the following disclaimer. */
+/*  2. Redistributions in binary form must reproduce the above copyright */
+/*     notice, this list of conditions and the following disclaimer in the */
+/*     documentation and/or other materials provided with the distribution. */
 
-/* ARGSUSED */
-int
-main(int argc, char *argv[])
+/*  Neither the name of the University nor the names of its contributors */
+/*  may be used to endorse or promote products derived from this software */
+/*  without specific prior written permission. */
+
+/*  THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR */
+/*  IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED */
+/*  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR */
+/*  PURPOSE. */
+
+extern int yylex ();
+
+int     main (argc, argv)
+     int     argc;
+     char   *argv[];
 {
-	while (yylex() != 0)
-		;
+	while (yylex () != 0) ;
 
 	return 0;
 }