Also enclose variable names with external linkage in __BEGIN_DECLS.

Doesn't matter much since C++ ABI used by GCC doesn't mangle variable
names;  however technically is required by Section 7.5 of the C++ spec.
Discussed with/OK guenther@, matthew@.

src/include/fenv.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: fenv.h,v 1.1 2011/04/21 21:12:56 martynas Exp $	*/
+/*	$OpenBSD: fenv.h,v 1.2 2011/05/25 21:46:49 martynas Exp $	*/
 /*	$NetBSD: fenv.h,v 1.2.4.1 2011/02/08 16:18:55 bouyer Exp $	*/
 
 /*
@@ -43,6 +43,7 @@ int	fetestexcept(int);
 
 int	fegetround(void);
 int	fesetround(int);
+
 int	fegetenv(fenv_t *);
 int	feholdexcept(fenv_t *);
 int	fesetenv(const fenv_t *);

src/include/math.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: math.h,v 1.28 2011/04/28 18:05:39 martynas Exp $	*/
+/*	$OpenBSD: math.h,v 1.29 2011/05/25 21:46:49 martynas Exp $	*/
 /*
  * ====================================================
  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
@@ -21,6 +21,7 @@
 #include <sys/cdefs.h>
 #include <sys/limits.h>
 
+__BEGIN_DECLS
 /*
  * ANSI/POSIX
  */
@@ -145,7 +146,6 @@ extern int signgam;
 #define	HUGE		MAXFLOAT
 #endif /* __BSD_VISIBLE */
 
-__BEGIN_DECLS
 /*
  * ANSI/POSIX
  */