Merge branch 'ab/tr2-leaks-and-fixes'

The tracing of process ancestry information has been enhanced. * ab/tr2-leaks-and-fixes: tr2: log N parent process names on Linux tr2: do compiler enum check in trace2_collect_process_info() tr2: leave the parent list empty upon failure & don't leak memory tr2: stop leaking "thread_name" memory tr2: clarify TRACE2_PROCESS_INFO_EXIT comment under Linux tr2: remove NEEDSWORK comment for "non-procfs" implementations