change benches to using criterion

[hkBst]

I wanted to try out criterion. So far it's... different.

[hkBst]

Now with an up to date version, somehow the criterion book is still based on an old version.

[tgross35]

Not sure what exactly you're going for but if perf is somewhat touchy in this repo, it might be worth checking out https://github.com/iai-callgrind/iai-callgrind. Nice that results are identical both on CI and locally (it's been running in compiler-builtins for ~6 months and I haven't noticed any noise, e.g. https://github.com/rust-lang/compiler-builtins/actions/runs/15858785039/job/44710523566#step:7:1356)

[hkBst]

Thanks @tgross35. I'll be sure to look into that.