This patch adds a <bits/types/res_state.h> header, to simplify
backporting.

diff --git a/include/bits/types/res_state.h b/include/bits/types/res_state.h
new file mode 100644
index 0000000000000000..568c768f444d0198
--- /dev/null
+++ b/include/bits/types/res_state.h
@@ -0,0 +1,2 @@
+#define __need_res_state
+#include <resolv.h>