addTargetQuery

    pub fn addTargetQuery(wip: *Wip, q: *const std.Target.Query) !TargetQuery.OptionalIndex {
        if (q.isNative()) return .none;
        const gpa = wip.gpa;
        const cpu_name: ?String = switch (q.cpu_model) {
            .native, .baseline, .determined_by_arch_os => null,
            .explicit => |model| try wip.addString(model.name),
        };
        const os_version_min: TargetQuery.OsVersion = if (q.os_version_min) |ver| switch (ver) {
            .none => .none,
            .semver => |sem_ver| .{ .semver = try wip.addSemVer(sem_ver) },
            .windows => |win_ver| .{ .windows = win_ver },
        } else .default;
        const os_version_max: TargetQuery.OsVersion = if (q.os_version_max) |ver| switch (ver) {
            .none => .none,
            .semver => |sem_ver| .{ .semver = try wip.addSemVer(sem_ver) },
            .windows => |win_ver| .{ .windows = win_ver },
        } else .default;
        const glibc_version: ?String = if (q.glibc_version) |sem_ver| try wip.addSemVer(sem_ver) else null;
        const dynamic_linker: ?String = if (q.dynamic_linker) |*dl|
            if (dl.get()) |s| try wip.addString(s) else .empty
        else
            null;
        const cpu_features_add_empty = q.cpu_features_add.isEmpty();
        const cpu_features_sub_empty = q.cpu_features_sub.isEmpty();
        const result_index: TargetQuery.Index = try wip.addExtra(TargetQuery, .{
            .flags = .{
                .cpu_arch = .init(q.cpu_arch),
                .cpu_model = .init(q.cpu_model),
                .cpu_features_add = !cpu_features_add_empty,
                .cpu_features_sub = !cpu_features_sub_empty,
                .os_tag = .init(q.os_tag),
                .abi = .init(q.abi),
                .object_format = .init(q.ofmt),
                .os_version_min = os_version_min,
                .os_version_max = os_version_max,
                .glibc_version = glibc_version != null,
                .android_api_level = q.android_api_level != null,
                .dynamic_linker = dynamic_linker != null,
            },
            .cpu_features_add = .{ .value = if (cpu_features_add_empty) null else q.cpu_features_add },
            .cpu_features_sub = .{ .value = if (cpu_features_sub_empty) null else q.cpu_features_sub },
            .glibc_version = .{ .value = glibc_version },
            .android_api_level = .{ .value = q.android_api_level },
            .dynamic_linker = .{ .value = dynamic_linker },
            .cpu_name = .{ .value = cpu_name },
            .os_version_min = .{ .u = os_version_min },
            .os_version_max = .{ .u = os_version_max },
        });

        // Deduplicate.
        const gop = try wip.targets_table.getOrPutContext(gpa, result_index, @as(TargetsTableContext, .{
            .extra = wip.extra.items,
        }));
        if (gop.found_existing) {
            wip.extra.items.len = @backingInt(result_index);
            return .init(gop.key_ptr.*);
        } else {
            return .init(result_index);
        }
    }