removes unused Object#remove_subclasses_of

activesupport/lib/active_support/core_ext/object/extending.rb

@@ -36,10 +36,6 @@ class Class
 end
 
 class Object
-  def remove_subclasses_of(*superclasses) #:nodoc:
-    Class.remove_class(*subclasses_of(*superclasses))
-  end
-
   # Exclude this class unless it's a subclass of our supers and is defined.
   # We check defined? in case we find a removed class that has yet to be
   # garbage collected. This also fails for anonymous classes -- please