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

… :)"

This reverts commit 21eadc1.

activerecord/lib/active_record/base.rb

@@ -2173,13 +2173,15 @@ def clear_timestamp_attributes
     # 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
 end