add workaround for level-triggered selectors

Like Windows, HermitOS based on level-triggered selectors.
Consequently, HermitOS depends on the workaround, which was written
for Windows.

tokio/src/io/poll_evented.rs

@@ -248,7 +248,7 @@ feature! {
                         // that the socket buffer is full.  Unfortunately this assumption
                         // fails for level-triggered selectors (like on Windows or poll even for
                         // UNIX): https://github.com/tokio-rs/tokio/issues/5866
-                        if n > 0 && (!cfg!(windows) && !cfg!(mio_unsupported_force_poll_poll) && n < buf.len()) {
+                        if n > 0 && (!(cfg!(windows) || cfg!(target_os = "hermit")) && !cfg!(mio_unsupported_force_poll_poll) && n < buf.len()) {
                             self.registration.clear_readiness(evt);
                         }