Corrected the implementation of IsPrimitive.
Corrected the implementation of IsPrimitive.

Signed-off-by: John Gietzen <565533dc8fd10856192adc18fcbade0f182446ed@gietzen.us>

hnafar/IronJS,hnafar/IronJS,hnafar/IronJS,xamarin/IronJS,fholm/IronJS,hnafar/IronJS,xamarin/IronJS,xamarin/IronJS,fholm/IronJS,xamarin/IronJS,fholm/IronJS,fholm/IronJS,hnafar/IronJS