vendors/execa.js/makeAllStream
var makeAllStream = (spawned, { all }) => {
  if (!all || !spawned.stdout && !spawned.stderr) {
    return;
  }
  const mixed = (0, import_merge_stream.default)();
  if (spawned.stdout) {
    mixed.add(spawned.stdout);
  }
  if (spawned.stderr) {
    mixed.add(spawned.stderr);
  }
  return mixed;
};