No longer works?

It seems this crate has stopped working recently, with the latest Rust update perhaps?

On my Intel Mac `cargo test` passes but `cargo test --release` fails for `test_buf_reader` and e.g. `test_copy` freezes.

On my M3 Mac `cargo test` fails for `test_buf_reader` and `test_copy`.

I originally noticed that something is wrong with code like this (that still worked fine a couple of months ago); now it works with `cargo run` but results in an infinite loop with `cargo run --release`, and it seems to read the same chunk over and over again:

```rust
use iconv::IconvReader;
use std::fs::File;
use std::io::{BufRead, BufReader};

fn main() {
let file = File::open("example.txt").unwrap();
let ireader = IconvReader::new(file, "utf-8", "utf-8").unwrap();
let mut br = BufReader::new(ireader);
let mut s = String::new();
while br.read_line(&mut s).unwrap() > 0 {
println!("{s:?}");
s.clear();
}
}
```