ravedude: Don't emit non-ascii bytes on Windows

Windows console stdio does not support sending UTF-8 sequences which
means that we must ensure that any data received from the serial
connection is cleaned to ASCII only before forwarding it to the console.

To make sure that users notice the illegal data getting sent, print `?`
symbols instead.

ravedude/src/console.rs

@@ -31,6 +31,16 @@ pub fn open(port: &std::path::Path, baudrate: u32) -> anyhow::Result<()> {
 
         match rx.read(&mut buf) {
             Ok(count) => {
+                #[cfg(target_os = "windows")]
+                {
+                    // On windows, we must ensure that we are not sending anything outside of the
+                    // ASCII range.
+                    for byte in &mut buf[..count] {
+                        if *byte & 0x80 != 0 {
+                            *byte = '?'.try_into().unwrap();
+                        }
+                    }
+                }
                 stdout.write(&buf[..count]).unwrap();
                 stdout.flush().unwrap();
             }