Use aggregate functions for stats dtype

[AdamGS]

Summary

We shouldn't implement the logic twice, IDK how this will deal with existing files but I guess that's why we have those tests?

[codspeed-hq]

Merging this PR will degrade performance by 17.02%

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

❌ 6 regressed benchmarks
✅ 1210 untouched benchmarks

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	new_bp_prim_test_between[i16, 32768]	120.8 µs	135.1 µs	-10.58%
❌	Simulation	new_bp_prim_test_between[i32, 16384]	95.2 µs	109.9 µs	-13.35%
❌	Simulation	new_bp_prim_test_between[i64, 16384]	115.6 µs	145.4 µs	-20.49%
❌	Simulation	new_alp_prim_test_between[f64, 16384]	127.5 µs	149.8 µs	-14.9%
❌	Simulation	new_bp_prim_test_between[i32, 32768]	141.5 µs	170.7 µs	-17.07%
❌	Simulation	new_bp_prim_test_between[i64, 32768]	178.5 µs	237.7 µs	-24.92%

Tip

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

---

_{Comparing adamg/use-aggregate-for-stat-type (95d691d) with develop (c0b6f31)}

[AdamGS]

😢 need to figure out back compact here

[joseph-isaacs]

Lets be careful about moving these over.