fix(codspeed): always compile instrument-hooks (with stubs)

[not-matthias]

No description provided.

[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #132 will not alter performance

_{Comparing simplify-instrument-hooks (8054636) with main (3de526b)}

Summary

✅ 186 untouched

[codspeed-hq]

CodSpeed WallTime Performance Report

Merging #132 will degrade performances by 50%

_{Comparing simplify-instrument-hooks (8054636) with main (3de526b)}

Summary

⚡ 18 improvements
❌ 13 regressions
✅ 137 untouched

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

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
⚡	build_vec	223 ns	208 ns	+7.21%
⚡	Recursive	52.5 µs	47.4 µs	+10.74%
⚡	Recursive[20]	52.5 µs	47.5 µs	+10.57%
⚡	Recursive[21]	84.9 µs	76 µs	+11.7%
⚡	small_drop	60 ns	53 ns	+13.21%
❌	large_setup	18 ns	20 ns	-10%
⚡	iter_batched_large_input	44 ns	40 ns	+10%
⚡	iter_batched_ref_large_input	44 ns	40 ns	+10%
⚡	iter_batched_ref_per_iteration	44 ns	40 ns	+10%
⚡	from_elem[16384]	986 ns	952 ns	+3.57%
❌	fibo_10	1 ns	2 ns	-50%
⚡	fib_10	427 ns	376 ns	+13.56%
⚡	fib_20	52.3 µs	45.6 µs	+14.73%
⚡	fib_30	6.5 ms	5.6 ms	+14.77%
❌	iterative[5]	7 ns	8 ns	-12.5%
⚡	recursive_memoized[BTreeMap<u64, u64>, 0]	18 ns	14 ns	+28.57%
❌	recursive_memoized[BTreeMap<u64, u64>, 5]	210 ns	221 ns	-4.98%
⚡	generate_combinations[5]	1,157 ns	908 ns	+27.42%
❌	generate_combinations[6]	1.8 µs	1.9 µs	-3.17%
❌	generate_combinations[7]	2.6 µs	3.3 µs	-19.42%
...	...	...	...	...

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

[Copilot]

Pull Request Overview

This PR refactors the codspeed crate to always compile the instrument-hooks with stub implementations for non-Linux platforms, instead of conditionally excluding them entirely. The main goal is to provide a unified API across all platforms while maintaining platform-specific optimizations.

Key changes:

• Removes conditional compilation guards that excluded instrument-hooks on non-Linux platforms
• Consolidates platform-specific implementations into a single struct with conditional behavior
• Updates error handling to use unsigned integers instead of signed integers

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
crates/codspeed/src/instrument_hooks/mod.rs	Unified InstrumentHooks implementation with platform-specific conditional logic instead of separate modules
crates/codspeed/instrument-hooks	Updated subproject commit reference
crates/codspeed/build.rs	Removed Linux-only compilation guard to build on all platforms
crates/codspeed/Cargo.toml	Made nix dependency Linux-specific using target-specific dependencies

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