FileUtil::mkdirUnique(): If the requested directory already exists, try multiple qualifiers (jobid and pid) instead of just one (pid).
FileUtil::mkdirUnique(): If the requested directory already exists,
try multiple qualifiers (jobid and pid) instead of just one (pid).

This makes a big difference for hpcprof-mpi on BG/P, where pid for
backend nodes are deterministic (since the OS boots each time).


zcth428/hpctoolkit,HPCToolkit/hpctoolkit,zcth428/hpctoolkit111,zcth428/hpctoolkit111,zcth428/hpctoolkit,zcth428/hpctoolkit,zcth428/hpctoolkit,zcth428/hpctoolkit111,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit,zcth428/hpctoolkit111,HPCToolkit/hpctoolkit,zcth428/hpctoolkit,HPCToolkit/hpctoolkit,zcth428/hpctoolkit111