Try storing an integer literal that requires 64 bits in a variable that can hold only 63 bits.
It's not going to make it impossible (you may just need something like a ShortIntLiteral and a LongIntLiteral variant), but it's going to require additional effort.
Sure, but not many real programs actually need the full 64-bits. Many of the ones that may seem to require the full bit width are doing bit ops on larger bit streams, for which there's ocaml-bitstream. What sort of programs are you thinking of?
