message: fix backward enumerate
diff: @@ -24,7 +24,7 @@ pub fn platform_fd_pread(
  )
  };
  nread.set(result as u32);
  - for (arr_cell, i) in iovs.iter().enumerate() {
  + for (i, arr_cell) in iovs.iter().enumerate() {
  let wasi_iovec = __wasi_iovec_t {
  buf: iovec[i] as _,
  buf_len: iovec[i].iov_len as u32,
  