Fix loss of precision in AnimClock and improve performance

[SUPERCILEX]

Old:

1s 320ms
Left: 140292640
Right: 140292630

New:

759ms
Success

[SUPERCILEX]

Oh, for whatever reason now I'm seeing ~1s time for the old version. The new one is still faster, but not by as much I guess.

[djeedai]

If you want stable results you need to bench it. This test is not warming the codepath before measuring, so will have variations per run. An ideal perf test runs the code first a few times so that all caches are hot and the CPU frequency scaling if any is already in power/perf mode (and ideally disables low-power and frequency scaling, but that's not always possible). That's probably good enough though given the large difference before/after.

[SUPERCILEX]

Yeah, I'm being very lazy. I mainly just wanted to check that using u128s wasn't slower than the old stuff.

[djeedai]

I'm going to merge as is for now, but I think the removal of times_completed will have to be reverted for #16 to work. Anyway, we'll see.

[SUPERCILEX]

Sounds good! I don't have time this week, but I'll start working on your ideas for #19 (unless you get to it first 😄) which will let me see what's still applicable in #21.