write file add new line

wasi/src/main.rs

@@ -3,7 +3,7 @@ use std::io::prelude::*;
 
 fn main() -> std::io::Result<()> {
     let mut file = File::create("foo.txt")?;
-    file.write_all(b"Hello, world!")?;
+    file.write_all(b"Hello, world!\n")?;
     println!("Hello, world!");
     Ok(())
 }