dirAccessWindows

fn dirAccessWindows(
    userdata: ?*anyopaque,
    dir: Dir,
    sub_path: []const u8,
    options: Dir.AccessOptions,
) Dir.AccessError!void {
    const t: *Threaded = @ptrCast(@alignCast(userdata));
    _ = t;

    _ = options; // TODO

    if (std.mem.eql(u8, sub_path, ".") or std.mem.eql(u8, sub_path, "..")) return;
    const sub_path_w = try sliceToPrefixedFileW(dir.handle, sub_path, .{});
    const attr: windows.OBJECT.ATTRIBUTES = .{
        .RootDirectory = if (Dir.path.isAbsoluteWindowsWtf16(sub_path_w.span())) null else dir.handle,
        .ObjectName = @constCast(&sub_path_w.string()),
    };
    var basic_info: windows.FILE.BASIC_INFORMATION = undefined;
    const syscall: Syscall = try .start();
    while (true) switch (windows.ntdll.NtQueryAttributesFile(&attr, &basic_info)) {
        .SUCCESS => return syscall.finish(),
        .CANCELLED => {
            try syscall.checkCancel();
            continue;
        },
        .OBJECT_NAME_NOT_FOUND => return syscall.fail(error.FileNotFound),
        .OBJECT_PATH_NOT_FOUND => return syscall.fail(error.FileNotFound),
        .OBJECT_NAME_INVALID => |err| return syscall.ntstatusBug(err),
        .INVALID_PARAMETER => |err| return syscall.ntstatusBug(err),
        .ACCESS_DENIED => return syscall.fail(error.AccessDenied),
        .OBJECT_PATH_SYNTAX_BAD => |err| return syscall.ntstatusBug(err),
        else => |rc| return syscall.unexpectedNtstatus(rc),
    };
}