Move id_value definition to the primary_key concern

Author: rafaelfranca

activerecord/lib/active_record/attribute_methods/primary_key.rb

@@ -152,6 +152,11 @@ def inherited(base)
                 @attributes_builder = nil
               end
             end
+
+            def load_schema! # :nodoc:
+              super
+              alias_attribute :id_value, :id if @columns_hash.key?("id")
+            end
         end
     end
   end

activerecord/lib/active_record/model_schema.rb

@@ -583,7 +583,6 @@ def load_schema!
           columns_hash = connection.schema_cache.columns_hash(table_name)
           columns_hash = columns_hash.except(*ignored_columns) unless ignored_columns.empty?
           @columns_hash = columns_hash.freeze
-          alias_attribute :id_value, :id if @columns_hash.key?("id")
         end
 
         # Guesses the table name, but does not decorate it with prefix and suffix information.