Avoid the nounistd option that doesn't exist on older flex, define YY_NO_UNISTD_H instead.

libs/wpp/ppl.l

@@ -128,7 +128,6 @@
 %option 8bit never-interactive
 %option nounput
 %option prefix="ppy_"
-%option nounistd
 
 %x pp_pp
 %x pp_eol
@@ -164,6 +163,10 @@ ul	[uUlL]|[uUlL][lL]|[lL][uU]|[lL][lL][uU]|[uU][lL][lL]|[lL][uU][lL]
 #include <ctype.h>
 #include <assert.h>
 
+#ifndef HAVE_UNISTD_H
+#define YY_NO_UNISTD_H
+#endif
+
 #include "wpp_private.h"
 #include "ppy.tab.h"
 

programs/winedbg/debug.l

@@ -19,13 +19,18 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  */
 
-%option nounput interactive 8bit prefix="dbg_" nounistd
+%option nounput interactive 8bit prefix="dbg_"
 
 %{
+#include "config.h"
 #include <stdlib.h>
 #include <string.h>
 #include <stdarg.h>
 
+#ifndef HAVE_UNISTD_H
+#define YY_NO_UNISTD_H
+#endif
+
 #include "debugger.h"
 #include "dbg.tab.h"
 

programs/winhelp/macro.lex.l

-%{
+%{ /* -*-C-*- */
 /*
  * Help Viewer
  *
@@ -20,10 +20,16 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  */
 %}
-%option nounput interactive 8bit nounistd
+%option nounput interactive 8bit
 %x quote
 %{
+#include "config.h"
 #include <assert.h>
+
+#ifndef HAVE_UNISTD_H
+#define YY_NO_UNISTD_H
+#endif
+
 #include "macro.h"
 
 #include "wine/debug.h"

tools/widl/parser.l

@@ -21,7 +21,6 @@
 %option stack
 %option nounput noyy_top_state
 %option 8bit never-interactive prefix="parser_"
-%option nounistd
 
 nl	\r?\n
 ws	[ \f\t\r]
@@ -45,8 +44,9 @@ double	[0-9]+\.[0-9]+([eE][+-]?[0-9]+)*
 #include <string.h>
 #include <ctype.h>
 #include <assert.h>
-#ifdef HAVE_UNISTD_H
-# include <unistd.h>
+
+#ifndef HAVE_UNISTD_H
+#define YY_NO_UNISTD_H
 #endif
 
 #include "widl.h"

tools/wrc/parser.l

@@ -87,7 +87,6 @@
 %option nounput noyy_top_state noyywrap
 %option 8bit never-interactive
 %option prefix="parser_"
-%option nounistd
 
 /* Some shortcut definitions */
 ws	[ \f\t\r]
@@ -97,12 +96,18 @@ cident	[a-zA-Z_][0-9a-zA-Z_]*
 
 /*#define LEX_DEBUG*/
 
+#include "config.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
 #include <assert.h>
 
+#ifndef HAVE_UNISTD_H
+#define YY_NO_UNISTD_H
+#endif
+
 #include "wine/unicode.h"
 #include "wrc.h"
 #include "utils.h"