windows fixes

crates/wasi-common/tokio/src/sched/windows.rs

@@ -8,7 +8,11 @@ pub async fn poll_oneoff<'a>(poll: &mut Poll<'a>) -> Result<(), Error> {
     // we use the blocking poll_oneoff implementation from the wasi-cap-std-crate.
     // We provide a function specific to this crate's WasiFile types for downcasting
     // to a RawHandle.
-    block_on_dummy_executor(move || poll_oneoff_(poll, wasi_file_raw_handle))
+    block_on_dummy_executor(move || poll_oneoff_(poll, wasi_file_is_stdin, wasi_file_raw_handle))
+}
+
+pub fn wasi_file_is_stdin(f: &dyn WasiFile) -> bool {
+    f.as_any().is::<crate::stdio::Stdin>()
 }
 
 fn wasi_file_raw_handle(f: &dyn WasiFile) -> Option<RawHandle> {