Implemented pthread_atfork()

Change-Id: Ie6c0bf593315d3507b3c4a6c8903a74a1fa053db
diff --git a/libc/include/pthread.h b/libc/include/pthread.h
index 944bb68..ecabdb1 100644
--- a/libc/include/pthread.h
+++ b/libc/include/pthread.h
@@ -233,6 +233,8 @@
 
 int pthread_setname_np(pthread_t thid, const char *thname);
 
+int pthread_atfork(void (*prepare)(void), void (*parent)(void), void(*child)(void));
+
 typedef void  (*__pthread_cleanup_func_t)(void*);
 
 typedef struct __pthread_cleanup_t {