Add guard

Author: wojtekmach

lib/elixir/lib/map.ex

@@ -539,7 +539,7 @@ defmodule Map do
     take!(keys, map, _acc = [])
   end
 
-  def take!(non_map, _keys) do
+  def take!(non_map, keys) when is_list(keys) do
     :erlang.error({:badmap, non_map})
   end