feat: add perf v2 support

[not-matthias]

Depends on CodSpeedHQ/instrument-hooks#9

[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #19 will degrade performances by 32.31%

_{Comparing cod-1379-codspeed-cpp-add-perf-v2-support (7c2430e) with main (dcb45c2)}

Summary

⚡ 6 improvements
❌ 3 regressions
✅ 61 untouched
🆕 6 new

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

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
❌	BM_Capture[int_test]	61.4 ns	90.6 ns	-32.21%
🆕	BM_SimpleMultithread	N/A	13.2 ms	N/A
🆕	BM_large_setup	N/A	13.2 ms	N/A
🆕	BM_large_setup_teardown	N/A	13.2 ms	N/A
⚡	BarTest[MyFixture]	90.8 ns	61.7 ns	+47.3%
⚡	DoubleTest[MyTemplatedFixture, double]	90.8 ns	61.7 ns	+47.3%
⚡	FooTest[MyFixture]	90.8 ns	61.7 ns	+47.3%
⚡	IntTest[MyTemplatedFixture, int]	90.8 ns	61.7 ns	+47.3%
⚡	TestA[MyTemplate1, int]	90.8 ns	61.7 ns	+47.3%
⚡	TestB[MyTemplate2, int, double]	90.8 ns	61.7 ns	+47.3%
❌	BM_Capture[int_test]	61.1 ns	90.3 ns	-32.31%
❌	BM_rand_vector	122.2 ns	151.4 ns	-19.27%
🆕	BM_SimpleMultithread	N/A	10.6 ms	N/A
🆕	BM_large_setup	N/A	10.6 ms	N/A
🆕	BM_large_setup_teardown	N/A	10.6 ms	N/A

[Copilot]

Pull Request Overview

Add wall-time instrumentation support for CodSpeed Perf v2 in the Google Benchmark integration and extend examples and CI to exercise and report the new mode.

• Track wall-time intervals across PauseTiming/ResumeTiming via measurement markers.
• Add example benchmarks (pause timing and multithread) and update CI to use the action mode input.
• Extend measurement helpers with timestamp/marker APIs and assertions.

Reviewed Changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
google_benchmark/src/benchmark.cc	Integrates wall-time markers on PauseTiming/ResumeTiming and initializes resume_timestamp_.
google_benchmark/include/benchmark/benchmark.h	Declares resume_timestamp_ and minor formatting in StateIterator; supports new instrumentation state.
core/include/measurement.hpp	Adds current timestamp/marker APIs and helper to record benchmark segments with asserts.
examples/google_benchmark_cmake/pause_timing_bench.hpp	Adds pause/resume timing example showcasing excluded work.
examples/google_benchmark_cmake/multithread_bench.hpp	Adds multithreaded example (spawn/join worker).
examples/google_benchmark_cmake/helper.hpp	Adds helper functions to simulate expensive work.
examples/google_benchmark_bazel/*	Reuse example headers from CMake examples.
.github/workflows/ci.yml	Switches to CodSpeed action mode input and simplifies env configuration.
core/instrument-hooks	Submodule bump to pick up new instrumentation hooks.

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[codspeed-hq]

CodSpeed WallTime Performance Report

Merging #19 will not alter performance

_{Comparing cod-1379-codspeed-cpp-add-perf-v2-support (4ae97f8) with main (dcb45c2)¹}

Summary

✅ 70 untouched
🆕 6 new

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
🆕	BM_SimpleMultithread	N/A	6.6 ms	N/A
🆕	BM_large_drop	N/A	1.1 ms	N/A
🆕	BM_large_setup	N/A	1.1 ms	N/A
🆕	BM_SimpleMultithread	N/A	6.6 ms	N/A
🆕	BM_large_drop	N/A	1.1 ms	N/A
🆕	BM_large_setup	N/A	1.1 ms	N/A

Footnotes

1. No successful run was found on main (7317f26) during the generation of this report, so dcb45c2 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

[art049]

looks good