grunt.loadNpmTasks('grunt-shimly');

// ...
    shimly: {
      // things you would like to shim (an array of items from the list above)
      shim: ['Array.filter', 'Function.bind', 'localStorage'],
      // output location (relative to your grunt.js file location)
      dest: 'build/shims.js',
      // minify the output (true or false)
      minify: false
    },
// ...