Work around build breakages with GCC 4.2.

Reported by:	tinderbox

contrib/openbsm/bin/auditdistd/token.l

@@ -52,6 +52,7 @@ int depth;
 int lineno;
 
 #define	DP	do { } while (0)
+#define	YY_DECL	int yylex(void)
 %}
 
 %option noinput

usr.bin/ar/acplex.l

@@ -40,6 +40,8 @@ int lineno = 1;
 
 int	yylex(void);
 
+#define	YY_DECL	int yylex(void)
+
 %}
 
 %option nounput

usr.bin/bc/scan.l

@@ -46,6 +46,7 @@ static void	 init_strbuf(void);
 static void	 add_str(const char *);
 static int	 bc_yyinput(char *, int);
 
+#define YY_DECL	int yylex(void)
 #define YY_NO_INPUT
 #undef YY_INPUT
 #define YY_INPUT(buf,retval,max) \

usr.bin/m4/tokenizer.l

@@ -31,6 +31,8 @@ extern int32_t yylval;
 int32_t number(void);
 int32_t parse_radix(void);
 extern int yylex(void);
+
+#define	YY_DECL	int yylex(void)
 %}
 
 delim 	[ \t\n]

usr.bin/mklocale/lex.l

@@ -47,6 +47,8 @@ __FBSDID("$FreeBSD$");
 #include "ldef.h"
 #include "y.tab.h"
 #include "extern.h"
+
+#define	YY_DECL	int yylex(void)
 %}
 
 ODIGIT	[0-7]

usr.sbin/bluetooth/bthidd/lexer.l

@@ -37,6 +37,8 @@
 #include "parser.h"
 
 	int	yylex	(void);
+
+#define	YY_DECL	int yylex(void)
 %}
 
 %option yylineno noyywrap nounput noinput

usr.sbin/config/lang.l

@@ -93,6 +93,7 @@ unsigned int octal(const char *);
 unsigned int hex(const char *);
 int yyerror(const char *);
 
+#define YY_DECL int yylex(void)
 %}
 
 %option nounput

usr.sbin/jail/jaillex.l

@@ -42,6 +42,8 @@ static ssize_t text2lval(size_t triml, size_t trimr, int tovar);
 
 static int instr;
 static int lineno = 1;
+
+#define YY_DECL int yylex(void)
 %}
 
 %option noinput