[Based on #112] debug: report debug and deployment artifact sizes

[cpunion]

Summary

Report final debug, deployment, and runtime-symbol artifacts with their physical format, exact on-disk size, and path.

The report distinguishes a host debug ELF from derived .bin/.hex/.img/.uf2/.zip deployment files, embedded Wasm DWARF from an external sidecar, and pclntab from debugger-owned DWARF. It runs after final linking, Wasm externalization, and target format conversion. Explicit -debug-artifact modes and named targets enable the report; ordinary native builds remain quiet.

Part of xgo-dev#2164 Task 1. Based on #112.

Validation

• macOS internal/build integration suite: 75.9% statement coverage after excluding the known stdio hang and independently covered PCLN integration groups
• artifact-report functions: 100% line coverage on macOS and Linux/amd64
• real external-DWARF WASI builds on macOS and Linux/amd64 report the deployable module and DWARF sidecar with exact sizes
• host ELF and derived deployment roles/formats, missing artifacts, and reporting failures are covered by focused tests
• the Cortex-M host ELF/.bin flow was validated before the dependency rebase; the current upstream baseline stops earlier in unrelated Go 1.26 bare-metal runtime code

[gemini-code-assist]

Caution

The consumer version of Gemini Code Assist on GitHub has been sunset. All code review activity has officially ceased.

[github-actions]

LLGo baseline benchmarks

b460595b924a | workflow run | long-term charts

Program measurements

Platform	Workload	File size	vs main	Build	vs main	Run	vs main
Linux	cprintf	18544 B	+0.0%	347.166 ms	-15.8% (better)	1.265 ms	-18.5% (better)
Linux	fmtprintf	2217608 B	+0.2% (worse)	3.307 s	-14.2% (better)	2.468 ms	-24.9% (better)
Linux	println	71504 B	-1.6% (better)	351.722 ms	-12.1% (better)	1.591 ms	-4.9% (better)
macOS	cprintf	84672 B	+0.0%	326.901 ms	-21.1% (better)	2.414 ms	-32.7% (better)
macOS	fmtprintf	2361520 B	+0.7% (worse)	2.599 s	-34.0% (better)	16.656 ms	-28.7% (better)
macOS	println	125712 B	-1.0% (better)	299.268 ms	-27.8% (better)	3.411 ms	-53.0% (better)

Core language and compiler benchmarks

Platform	Benchmark	ns/op	vs main
Linux	BenchmarkLookupPCRandom	13.410 ns/op	-0.5% (better)
Linux	BenchmarkMergeCompilerFlags	151.100 ns/op	-2.2% (better)
Linux	BenchmarkMergeLinkerFlags	96.040 ns/op	-5.2% (better)
Linux	BenchmarkChannelBuffered	33.990 ns/op	-2.2% (better)
Linux	BenchmarkChannelHandoff	29432 ns/op	-8.1% (better)
Linux	BenchmarkDefer	44.210 ns/op	-21.5% (better)
Linux	BenchmarkDirectCall	1.557 ns/op	-0.4% (better)
Linux	BenchmarkGlobalRead	1.873 ns/op	+20.1% (worse)
Linux	BenchmarkGlobalWrite	2.497 ns/op	+0.1% (worse)
Linux	BenchmarkGoroutine	32532 ns/op	-57.0% (better)
Linux	BenchmarkInterfaceCall	8.096 ns/op	+3.9% (worse)
Linux	BenchmarkRuntimeGetG	1.867 ns/op	-64.8% (better)
macOS	BenchmarkLookupPCRandom	10.850 ns/op	-12.8% (better)
macOS	BenchmarkMergeCompilerFlags	94.280 ns/op	-24.3% (better)
macOS	BenchmarkMergeLinkerFlags	64.460 ns/op	-7.1% (better)
macOS	BenchmarkChannelBuffered	23.760 ns/op	-14.3% (better)
macOS	BenchmarkChannelHandoff	5186 ns/op	-26.0% (better)
macOS	BenchmarkDefer	30.670 ns/op	-18.1% (better)
macOS	BenchmarkDirectCall	1.053 ns/op	-27.5% (better)
macOS	BenchmarkGlobalRead	1.030 ns/op	-14.9% (better)
macOS	BenchmarkGlobalWrite	1.082 ns/op	-27.2% (better)
macOS	BenchmarkGoroutine	29053 ns/op	-8.2% (better)
macOS	BenchmarkInterfaceCall	4.842 ns/op	-10.3% (better)
macOS	BenchmarkRuntimeGetG	2.188 ns/op	-15.1% (better)

Compared only with the latest matching platform in the main series.

Warning

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