perf tests: Add test for uncore event sorting

perf tests: Add test for uncore event sorting

Add a test for uncore event sorting matching multiple PMUs.

Uncore PMUs may have a common prefix, like the PMUs
uncore_imc_free_running_0 and uncore_imc_free_running_1 have a prefix of
uncore_imc_free_running.

Parsing an event group like "{data_read,data_write}" for those PMUs
should result with two groups:

  "{uncore_imc_free_running_0/data_read/,uncore_imc_free_running_0/data_write/},
   {uncore_imc_free_running_1/data_read/,uncore_imc_free_running_1/data_write/}"

which means the evsels need resorting as when initially parsed the
evsels are ordered with mixed PMUs:

  "{uncore_imc_free_running_0/data_read/,uncore_imc_free_running_1/data_read/,
  uncore_imc_free_running_0/data_write/,uncore_imc_free_running_1/data_write/}".

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Zide Chen <zide.chen@intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Collin Funk <collin.funk1@gmail.com>
Cc: Dmitrii Dolgov <9erthalion6@gmail.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>