Webxr: Should XRRigidTransform reject non-finite values

[cabanier]

XRRigidTransform currently doesn't have any validation on the values it takes in its constructor.
So, if the author passes NaN values, they will be forwarded to the WebXR internals and driver which might cause crashes or other undefined behavior.

XRRigidTransform should do some simple validation and reject non-sensical values.

[Manishearth]

It already does, WebIDL floats are finite. There's unrestricted float if you want non-finite values. If your browser is allowing infinite floats in the constructor, that's a bug in its webidl bindings generation implementation.

[cabanier]

@Manishearth not so fast :-)
The XRRigidTransform constructor takes 2 DOMPointInits that allow unrestricted doubles.

[Manishearth]

oh HUH.

I think we should just fix this then