google/traceur-compiler — pull request #1410 by DmitrySoshnikov (2014-10-09 04:34:23+00:00)
Title: [Polyfill] Don't skip holes in Array#find and Array#findIndex

Per Rev27 of ES6 draft, `Array.prototype.find` and `Array.prototype.findIndex` do not skip holes anymore.

[1] http://people.mozilla.org/~jorendorff/es6-draft.html#sec-array.prototype.find