Add complete struct timeval by including <sys/_timeval.h>.

sys/sys/select.h

@@ -40,15 +40,9 @@
 #include <sys/_types.h>
 
 #include <sys/_sigset.h>
+#include <sys/_timeval.h>
 #include <sys/timespec.h>
 
-/*
- * XXX
- * Other things required for this header which we do not presently implement:
- *
- * struct timeval (with suseconds_t)
- */
-
 typedef	unsigned long	__fd_mask;
 #if __BSD_VISIBLE
 typedef	__fd_mask	fd_mask;
@@ -103,7 +97,6 @@ typedef	struct fd_set {
 } while (0)
 
 #ifndef _KERNEL
-struct timeval;
 
 __BEGIN_DECLS
 int pselect(int, fd_set *__restrict, fd_set *__restrict, fd_set *__restrict,