Fix benchmark test problem on Windows

Author: yhirose

httplib.h

@@ -3283,7 +3283,10 @@ inline ssize_t select_write(socket_t sock, time_t sec, time_t usec) {
 
 inline Error wait_until_socket_is_ready(socket_t sock, time_t sec,
                                         time_t usec) {
-#ifdef __APPLE__
+#if defined(__APPLE__) || defined(_WIN32)
+  // Use select() on macOS and Windows for better performance with localhost
+  // connections. WSAPoll() on Windows has known performance issues with
+  // localhost.
   if (sock >= FD_SETSIZE) { return Error::Connection; }
 
   fd_set fdsr, fdsw;