serializeCpu

pub fn serializeCpu(buffer: *std.array_list.Managed(u8), cpu: std.Target.Cpu) Allocator.Error!void {
    const all_features = cpu.arch.allFeaturesList();
    var populated_cpu_features = cpu.model.features;
    populated_cpu_features.populateDependencies(all_features);

    try buffer.appendSlice(cpu.model.name);

    if (populated_cpu_features.eql(cpu.features)) {
        // The CPU name alone is sufficient.
        return;
    }

    for (all_features, 0..) |feature, i_usize| {
        const i: std.Target.Cpu.Feature.Set.Index = @intCast(i_usize);
        const in_cpu_set = populated_cpu_features.isEnabled(i);
        const in_actual_set = cpu.features.isEnabled(i);
        try buffer.ensureUnusedCapacity(feature.name.len + 1);
        if (in_cpu_set and !in_actual_set) {
            buffer.appendAssumeCapacity('-');
            buffer.appendSliceAssumeCapacity(feature.name);
        } else if (!in_cpu_set and in_actual_set) {
            buffer.appendAssumeCapacity('+');
            buffer.appendSliceAssumeCapacity(feature.name);
        }
    }
}