Function foreach

src/tests/containerizer/rootfs.cpp:145–155

  };

  foreach (const string& program, programs) {
    Try<hashset<string>> dependencies = ldd(program, cache.get());
    if (dependencies.isError()) {
      return Error(
          "Failed to find dependencies for '" + program + "': " +
          dependencies.error());
    }

    files |= dependencies.get();
    files.insert(program);
  }

  foreach (const string& file, files) {
    Try<Nothing> result = rootfs->add(file);