using . (dot) reference syntax on a map fails when value is a function

```elixir
#Good
map = %{test_map: 111}
map.test_map

#Good
map = %{test_map: &Map.get/2}
Map.get(map, :test_map)

#Bad
map = %{test_map: &Map.get/2}
map.test_map

#Uncaught MatchError: No match for: 
```

Note that Map.get/2 still works in the Bad case.