Make ref return the internal symbol.

We delegate to_sym to the internal symbol, which we've already called to_sym on in
initialize, so we don't need to do that.

We also know to_sym will never return a falsy value, so we'll never hit to_s.

Just return the symbolized symbol.

actionview/lib/action_view/template/types.rb

@@ -32,7 +32,7 @@ def initialize(symbol)
         alias to_str to_s
 
         def ref
-          to_sym || to_s
+          @symbol
         end
 
         def ==(type)