getOwnPropertyDescriptor causes fatal error in IE8

[debugwand]

Within can/construct/construct.js, this line will throw an error in IE8
var descriptor = Object.getOwnPropertyDescriptor(newProps, name);

This is because IE8 will only support getOwnPropertyDescriptor on DOM objects but not user defined objects.
http://msdn.microsoft.com/en-us/library/ie/dd548686(v=vs.94).aspx

Versions affected: 2.1.4

IE7 works

Additional comment: took out all js files apart from jQuery and can.custom.js to check. Can.custom.js had been built with can.Map, which includes can.Construct.

[daffl]

Argh, I thought I tested this in IE8. I guess the solution is to feature detect this (see https://github.com/es-shims/es5-shim/blob/master/es5-sham.js#L73)