options: { compat: true }
notes: """
  It's possible for `undefined` to be redefined in JavaScript, eg, `var
  undefined = 2`. While this is undesirable and never recommended, Js2coffee
  will that using `undefined` will use whatever `undefined` is defined as.
  This is only available if compatibility mode is on (`--compat`).
"""
----
undefined
----
`undefined`
