JS driver - Maximum call stack size exceeded on big arrays

While doing some random tests, I found that this fails with a `RangeError: Maximum call stack size exceeded`

``` javascript
var a = eval('['+new Array(100002).join('{}, ')+'{}]');
r.expr(a)
```

It's also broken in 1.13.x
And it works fine with rethinkdbdash. Maybe it's a coffee-script issue?
