Revert "Base#[] and Base#[]= are aliases so implement them as aliases :)"

This reverts commit 21eadc1b.

activerecord/lib/active_record/attribute_methods.rb

@@ -20,13 +20,15 @@ module AttributeMethods #:nodoc:
       # Returns the value of the attribute identified by <tt>attr_name</tt> after it has been typecast (for example,
       # "2004-12-12" in a data column is cast to a date object, like Date.new(2004, 12, 12)).
       # (Alias for the protected read_attribute method).
-      alias [] read_attribute
+      def [](attr_name)
+        read_attribute(attr_name)
+      end
 
       # Updates the attribute identified by <tt>attr_name</tt> with the specified +value+.
       # (Alias for the protected write_attribute method).
-      alias []= write_attribute
-
-      public :[], :[]=
+      def []=(attr_name, value)
+        write_attribute(attr_name, value)
+      end
     end
 
     module ClassMethods