build/linux/libcxx-fetcher.ts/downloadLibcxxObjects
export async function downloadLibcxxObjects(outDir: string, electronVersion: string, targetArch: string = 'x64'): Promise<void> {
	if (await fs.pathExists(path.resolve(outDir, 'libc++.a'))) {
		return;
	}
	if (!await fs.pathExists(outDir)) {
		await fs.mkdirp(outDir);
	}

	d(`downloading libcxx-objects-linux-${targetArch}`);
	const objects = await downloadArtifact({
		version: electronVersion,
		platform: 'linux',
		artifactName: 'libcxx-objects',
		arch: targetArch,
	});

	d(`unpacking libcxx-objects from ${objects}`);
	await extract(objects, { dir: outDir });
}