We still fallback to an idle server, but this prevents a client from
connecting to a named pipe server that isn't listening.

ntdll: The FileMailslotSetInformation and FileCompletionInformation cases of NtSetInformationFile don't need the fd.

So don't do an extra server call to get the fd to avoid a performance
penalty and to make these cases work when an fd isn't available.

Use a local header file for them.

Get rid of infinite loops when run's width was larger than the global
available width.