sched_yield netbsd (anselm garbe)

include/libc.h

diff --git a/include/libc.h b/include/libc.h
index 3c5537e..65c23dd 100644
--- a/include/libc.h
+++ b/include/libc.h
@@ -900,7 +900,8 @@
 #	endif
 #endif
 
-#if defined(__OpenBSD__)
+/* this really shouldn't be here */
+#if defined(__OpenBSD__) || (defined(__NetBSD__) && !defined(sched_yield))
 #define sched_yield() \
 	do { \
 		struct timespec ts; \