functypes: provide the recv and send arg and return types

This header is for providing the argument types for recv() and send()
when built to not use a dedicated config-[platfor].h file.

Remove the slow brute-force checks from configure and cmake.

This change also removes the use of the types for select, as they were
not used in code.

Closes #9592

lib/memdebug.h

@@ -31,6 +31,7 @@
  */
 
 #include <curl/curl.h>
+#include "functypes.h"
 
 #if defined(__GNUC__) && __GNUC__ >= 3
 #  define ALLOC_FUNC __attribute__((malloc))