simplify singleton_class? method

activesupport/lib/active_support/core_ext/class/attribute.rb

@@ -110,12 +110,6 @@ def #{name}?
 
   private
   def singleton_class?
-    # in case somebody is crazy enough to overwrite allocate
-    allocate = Class.instance_method(:allocate)
-    # object.class always points to a real (non-singleton) class
-    allocate.bind(self).call.class != self
-  rescue TypeError
-    # MRI/YARV/JRuby all disallow creating new instances of a singleton class
-    true
+    !name || '' == name
   end
 end