chore: use std::hint::black_box

[DaniPopes]

It has been stable for quite a while now.

[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #97 will degrade performances by 18.88%

_{Comparing DaniPopes:std-black-box (6178dd1) with main (6cb8d30)}

Summary

⚡ 5 improvements
❌ 7 regressions
✅ 155 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
❌	a	254.7 ns	281.4 ns	-9.48%
❌	a	254.7 ns	281.4 ns	-9.48%
❌	fibo_iterative	126.7 ns	156.1 ns	-18.86%
❌	sum_fold	254.4 ns	283.9 ns	-10.37%
⚡	sleep_100ms	566.1 ns	536.9 ns	+5.43%
⚡	sleep_10ms	566.1 ns	536.9 ns	+5.43%
⚡	sleep_50ms	566.1 ns	536.9 ns	+5.43%
⚡	from_elem[1024]	1.9 µs	1.8 µs	+3.27%
⚡	from_elem_decimal[1024]	1.9 µs	1.8 µs	+3.27%
❌	bench_array1[4]	125.3 ns	154.4 ns	-18.88%
❌	bench_array2[4]	125.3 ns	154.4 ns	-18.88%
❌	init_array[4]	125.3 ns	154.4 ns	-18.88%

[codspeed-hq]

CodSpeed WallTime Performance Report

Merging #97 will degrade performances by 64.26%

_{Comparing DaniPopes:std-black-box (6178dd1) with main (6cb8d30)}

Summary

⚡ 8 improvements
❌ 7 regressions
✅ 139 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
⚡	build_vec	215 ns	202 ns	+6.44%
❌	large_drop	172.7 µs	180.1 µs	-4.12%
⚡	large_setup	12 ns	10 ns	+20%
⚡	from_elem[1024]	82 ns	79 ns	+3.8%
❌	from_elem[2048]	248 ns	261 ns	-4.98%
⚡	from_elem_decimal[1024]	82 ns	79 ns	+3.8%
⚡	from_elem_decimal[2048]	256 ns	244 ns	+4.92%
⚡	recursive_memoized[BTreeMap<u64, u64>, 0]	17 ns	14 ns	+21.43%
❌	hamiltonian_cycle[5]	663 ns	696 ns	-4.74%
❌	permutations[5]	10.8 µs	11.4 µs	-5.37%
❌	permutations[7]	760.5 µs	797.1 µs	-4.59%
❌	sleep_100ns	17.6 µs	49.2 µs	-64.26%
❌	sleep_100us	121.4 µs	133.1 µs	-8.82%
⚡	sleep_1ns	40.1 µs	37.4 µs	+7.42%
⚡	sleep_1us	58.4 µs	34.8 µs	+67.69%

[not-matthias]

LGTM!

[art049]

Thanks for the contribution @DaniPopes