aux-output events need to have an AUX area event as the group leader.
However, grouping events does not allow the AUX area event to be given
an address filter because the --filter option must come after the event,
which conflicts with the grouping syntax.

To allow filtering in that case, automatically create a group since that
is the requirement anyway.

Example: (requires Intel Tremont)

  perf record -c 500 -e 'intel_pt//u' --filter 'filter main @ /bin/ls' -e 'cycles/aux-output/pp' ls
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20210121140418.14705-1-adrian.hunter@intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>