The attached patch enhances the robustness of ITrace when tracing
multiple processes simultaneously (e.g., via ITrace_On_GTPID() or
run.itrace). One of the changes made in this patch is to exclude the
tracing of *all* kernel threads since tracing certain kernel threads is
very problematic for ITrace. A mechanism is needed in the tooling to
allow the user to request tracking of particular kernel threads.