emberjs/ember.js — pull request #5421 by rwjblue (2014-08-18 11:53:17+00:00)
Title: Ensure defineProperties shim has a defineProperty to use.

The Object.create shim uses a `defineProperty` local function, but in the case of IE8 we nullify the `defineProperty` local function and never reset it to what we use for `platform.defineProperty`.