FileUtils#fu_split_path

# File tmp/rubies/ruby-3.3.0/lib/fileutils.rb, line 2506
def fu_split_path(path)
  path = File.path(path)
  list = []
  until (parent, base = File.split(path); parent == path or parent == ".")
    list << base
    path = parent
  end
  list << path
  list.reverse!
end