feat(preview1): implement poll_oneoff

Signed-off-by: Roman Volosatovs <[email protected]>

Author: rvolosatovs

crates/test-programs/tests/wasi-preview1-host-in-preview2.rs

@@ -258,13 +258,10 @@ async fn path_symlink_trailing_slashes() {
     run("path_symlink_trailing_slashes", false).await.unwrap()
 }
 #[test_log::test(tokio::test(flavor = "multi_thread"))]
-#[should_panic]
 async fn poll_oneoff_files() {
     run("poll_oneoff_files", false).await.unwrap()
 }
 #[test_log::test(tokio::test(flavor = "multi_thread"))]
-// This is a known bug with the preview 2 implementation:
-#[should_panic]
 async fn poll_oneoff_stdio() {
     run("poll_oneoff_stdio", true).await.unwrap()
 }