Extend `finite?` and `nan?` to non-real values
|Reported by:||cowan||Owned by:||cowan|
|Component:||WG1 - Core||Keywords:|
R6RS specifies the domain of finite? and nan? as the real numbers only. I propose that finite? return #t on a non-real value iff both the real part and the imaginary part are finite and not +nan.0, and that nan? return #t on a non-real value iff either the real or the imaginary part is +nan.0.