feat(criterion-compat): add iter_manual to have finer control over the iteration loop

[GuillaumeLagrange]

No description provided.

[codspeed-hq]

Merging this PR will not alter performance

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 15 improved benchmarks
❌ 9 regressed benchmarks
✅ 551 untouched benchmarks
🆕 8 new benchmarks

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	WallTime	iter_batched_large_input	8 ns	6 ns	+33.33%
⚡	WallTime	iter_batched_per_iteration	56 ns	46 ns	+21.74%
⚡	WallTime	iter_batched_ref_large_input	6 ns	5 ns	+20%
❌	WallTime	slice_into_vec_with_bytes	54 ns	94 ns	-42.55%
⚡	WallTime	iterative[20]	41 ns	38 ns	+7.89%
❌	WallTime	generate_combinations[5]	1.2 µs	1.5 µs	-24.63%
❌	WallTime	add_two_integers[(65535, -65535)]	75 ns	89 ns	-15.73%
❌	WallTime	graph_coloring[5]	1.1 µs	1.4 µs	-21.92%
❌	WallTime	hamiltonian_cycle[5]	845 ns	920 ns	-8.15%
⚡	WallTime	add_two_integers[(255, 255)]	20 ns	6 ns	×3.3
⚡	WallTime	iter_with_setup	60 ns	47 ns	+27.66%
🆕	WallTime	iter_manual_simple	N/A	100.1 ms	N/A
🆕	WallTime	iter_manual_with_external_setup	N/A	4.6 µs	N/A
⚡	WallTime	from_elem_decimal[1024]	85 ns	80 ns	+6.25%
❌	WallTime	sum_fold	309 ns	322 ns	-4.04%
❌	WallTime	bench_array1[42]	47 ns	179 ns	-73.74%
❌	WallTime	fib_10	392 ns	419 ns	-6.44%
❌	Simulation	process_items_with_counter	835.8 ns	865 ns	-3.37%
🆕	Memory	iter_manual_async	N/A	0 B	N/A
🆕	Memory	iter_manual_simple	N/A	0 B	N/A
...	...	...	...	...	...

ℹ️ Only the first 20 benchmarks are displayed. Go to the app to view all benchmarks.

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing cod-2677-add-a-custom-iter-in-codspeed-criterion-to-support-custom (e8a25a8) with main (6c54971)}

[not-matthias]

LGTM!