Feature request: More `Float` primitives.

[EdAyers]

Please could we have the following primitives available for Float. I think they can all be implemented in terms of the other primitives but they would be nice to have explicitly. The particular problem I am trying to solve is writing a JSON encoding for Float (ideally without going via a string). I had a go at adding these but I couldn't get the bootstrapping to work.

• isinf
• isnan
• isfinite
• frexp
• I'm not sure what the appropriate primitive is, but getting the integer mantissa and exponent from a Float in a platform-safe way.

[digama0]

I can try to implement this if the devs are okay with it.

[leodemoura]

I can try to implement this if the devs are okay with it.

@digama0 Thanks for volunteering. Please go ahead.