Hello Simon,
Thanks for pointing these out to me. I won't be able to look into this for the next week, but from what I could see so far, #2760 seems easy: copy mkNorepType to mkNoRepType, mark mkNorepType as deprecated and replace usage everywhere to avoid warnings and pass validation. I can submit the patch for this.
#2759 has some deeper implications, though. Replacing the FloatConstr Double by FloatConstr Rational might break existing client code (even though it probably wouldn't be too hard to fix it). Additionally, I see that the serializer code in compiler/utils/Serialized.hs would also need changes (it's no longer serializing a Double). But I guess this is also not too problematic...
Cheers,
Pedro