code: function ArrayFill(value, start, end) {
    CHECK_OBJECT_COERCIBLE(this, "Array.prototype.fill");
  
    var array = TO_OBJECT(this);
    var length = TO_LENGTH(array.length);
  
    return InnerArrayFill(value, start, end, array, length);
  }
docs: ES6, draft 04-05-14, section 22.1.3.6