> 128-bit integer type? Yes, should be coming with C's _BitInt(N).

I'm taking the first steps towards getting that into C++ btw.
https://isocpp.org/files/papers/P3639R0.html

I've also made a proposal for 128-bit integers before, but I think
it's just not high-consensus enough and I at least want to test the
waters for _BitInt first.