perf test: Workload test of metric and metricgroups

Test every metric and metricgroup with 'true' as a workload. For
metrics, check that we see the metric printed or get unsupported. If the
'true' workload executes too quickly retry with 'perf bench internals
synthesize'.

v3. Fix test condition (thanks to Paul A. Clarke <pc@us.ibm.com>). Add a
    fallback case of a larger workload so that we don't ignore "<not
    counted>".
v2. Switched the workload to something faster.

Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20210917184240.2181186-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>