[Bug libstdc++/66059] make_integer_sequence should use a log(N) implementation

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66059

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I already have a better make_integer_sequence, but have been trying to write an
intrinsic.