mikros: Close files on drop

library/std/src/sys/pal/mikros/fs.rs

@@ -375,6 +375,19 @@ pub fn set_times(&self, _times: FileTimes) -> io::Result<()> {
     }
 }
 
+impl Drop for File {
+    fn drop(&mut self) {
+        let _ = &rpc::send_call(
+            self.fs_pid,
+            1,
+            2,
+            &postcard::to_allocvec(&self.fd)
+            .unwrap(),
+        )
+        .get_return();
+    }
+}
+
 impl DirBuilder {
     pub fn new() -> DirBuilder {
         DirBuilder {}