Always include <sys/cdefs.h> first.

Otherwise you can't be sure that things like __BIONIC__ work.

Change-Id: Ic5e59988b69419828c3b1a97332c7e2ab58e09a1
diff --git a/libc/include/resolv.h b/libc/include/resolv.h
index f25484a..4367359 100644
--- a/libc/include/resolv.h
+++ b/libc/include/resolv.h
@@ -29,9 +29,10 @@
 #ifndef _RESOLV_H_
 #define _RESOLV_H_
 
+#include <sys/cdefs.h>
+
 #include <sys/param.h>
 #include <sys/types.h>
-#include <sys/cdefs.h>
 #include <sys/socket.h>
 #include <stdio.h>
 #include <arpa/nameser.h>