Merge pull request #4187 from castlerock/basic_object_in_19

::BasicObject always defined in ruby 19

activesupport/lib/active_support/basic_object.rb

 module ActiveSupport
-  if defined? ::BasicObject
   # A class with no predefined methods that behaves similarly to Builder's
   # BlankSlate. Used for proxy classes.
   class BasicObject < ::BasicObject
@@ -11,11 +10,5 @@ def raise(*args)
       ::Object.send(:raise, *args)
     end
   end
-  else
-    class BasicObject #:nodoc:
-      instance_methods.each do |m|
-        undef_method(m) if m.to_s !~ /(?:^__|^nil\?$|^send$|^object_id$)/
-      end
-    end
-  end
+
 end