backport_spec_file

# File lib/bundler/rubygems_integration.rb, line 563
    def backport_spec_file
      redefine_method(Gem::Specification, :spec_dir) do
        @spec_dir ||= File.join base_dir, "specifications"
      end

      redefine_method(Gem::Specification, :spec_file) do
        @spec_file ||= File.join spec_dir, "#{full_name}.gemspec"
      end
    end