rename_column_indexes

# File activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb, line 1648
        def rename_column_indexes(table_name, column_name, new_column_name)
          column_name, new_column_name = column_name.to_s, new_column_name.to_s
          indexes(table_name).each do |index|
            next unless index.columns.include?(new_column_name)
            old_columns = index.columns.dup
            old_columns[old_columns.index(new_column_name)] = column_name
            generated_index_name = index_name(table_name, column: old_columns)
            if generated_index_name == index.name
              rename_index table_name, generated_index_name, index_name(table_name, column: index.columns)
            end
          end
        end