Bug when transpiling funtion call with escaped atoms in name

[eksperimental]

-module(debug).
-compile(export_all).

function_names() ->
  '__function_names__'().

'__function_names__'() ->
  'foo'.

transpiles to

defmodule :debug do
  use Bitwise
  @compile :export_all
  def function_names() do
    '__function_names__'()
  end

  def __function_names__() do
    :foo
  end

end

which errors,

$ elixirc debug.ex

== Compilation error in file debug.ex ==
** (SyntaxError) debug.ex:5:25: syntax error before: '('

[eksperimental]

@marianoguerra there are a few more issues, but I will see if they are fixed once these last two bugs are covered. I will submit them if they are not.