Enable lttng tracing (doesn't work)
Builds tor with lttng tracing, and enables it at run time. The goal was to have the simulated tor processes talk to the real lttng daemon on the host machine, but it doesn't look like it's going to work. lttng clients try to pass a file descriptor to the daemon over a named unix socket. I don't think shadow implements passing file descriptors over sockets at all, and definitely not from a simulated process to a native process.