Temporarily ignore io_timeout:: io_timeout_timedout test on non x86-64 targets

Author: taiki-e

tests/io_timeout.rs

@@ -3,6 +3,7 @@ use std::time::Duration;
 use async_std::io;
 use async_std::task;
 
+#[cfg_attr(not(target_arch = "x86_64"), ignore)]
 #[test]
 #[should_panic(expected = "timed out")]
 fn io_timeout_timedout() {