message: with isolation we want to be fully deterministic
diff: @@ -1694,7 +1694,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
  fn isatty(&mut self, miri_fd: &OpTy<'tcx, Tag>) -> InterpResult<'tcx, i32> {
  let this = self.eval_context_mut();
  #[cfg(unix)]
  - {
  + if matches!(this.machine.isolated_op, IsolatedOp::Allow) {
  let miri_fd = this.read_scalar(miri_fd)?.to_i32()?;
  if let Some(host_fd) =
  this.machine.file_handler.handles.get(&miri_fd).and_then(|fd| fd.as_unix_host_fd())
  @@ -1714,7 +1714,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
  }
  }
  // We are attemping to use a Unix interface on a non-Unix platform, or we are on a Unix
  - // platform and the passed file descriptor is not open.
  + // platform and the passed file descriptor is not open, or isolation is enabled
  // FIXME: It should be possible to emulate this at least on Windows by using
  // GetConsoleMode.
  let enotty = this.eval_libc("ENOTTY")?;
  