Support Hermit without cfg flags

Author: Thomasdezeeuw

src/poll.rs

@@ -1,7 +1,12 @@
 #[cfg(all(
     unix,
     not(mio_unsupported_force_poll_poll),
-    not(any(target_os = "espidf", target_os = "solaris", target_os = "vita")),
+    not(any(
+        target_os = "espidf",
+        target_os = "hermit",
+        target_os = "solaris",
+        target_os = "vita"
+    )),
 ))]
 use std::os::unix::io::{AsRawFd, RawFd};
 #[cfg(all(debug_assertions, not(target_os = "wasi")))]
@@ -430,7 +435,12 @@ impl Poll {
 #[cfg(all(
     unix,
     not(mio_unsupported_force_poll_poll),
-    not(any(target_os = "espidf", target_os = "solaris", target_os = "vita")),
+    not(any(
+        target_os = "espidf",
+        target_os = "hermit",
+        target_os = "solaris",
+        target_os = "vita"
+    )),
 ))]
 impl AsRawFd for Poll {
     fn as_raw_fd(&self) -> RawFd {
@@ -721,7 +731,12 @@ impl fmt::Debug for Registry {
 #[cfg(all(
     unix,
     not(mio_unsupported_force_poll_poll),
-    not(any(target_os = "espidf", target_os = "solaris", target_os = "vita")),
+    not(any(
+        target_os = "espidf",
+        target_os = "hermit",
+        target_os = "solaris",
+        target_os = "vita"
+    )),
 ))]
 impl AsRawFd for Registry {
     fn as_raw_fd(&self) -> RawFd {
@@ -733,7 +748,7 @@ cfg_os_poll! {
     #[cfg(all(
         unix,
         not(mio_unsupported_force_poll_poll),
-        not(any(target_os = "espidf", target_os = "solaris", target_os = "vita")),
+        not(any(target_os = "espidf", target_os = "hermit", target_os = "solaris", target_os = "vita")),
     ))]
     #[test]
     pub fn as_raw_fd() {

src/sys/unix/waker.rs

@@ -168,14 +168,12 @@ mod eventfd {
     any(
         target_os = "android",
         target_os = "espidf",
+        target_os = "hermit",
         target_os = "linux",
     )
 ))]
 pub(crate) use self::eventfd::WakerInternal;
 
-#[cfg(target_os = "hermit")]
-pub(crate) use self::eventfd::WakerInternal;
-
 #[cfg(all(
     not(mio_unsupported_force_waker_pipe),
     any(