perf tests: Add perf script test

perf tests: Add perf script test

Start a new set of shell tests for testing perf script. The initial
contribution is checking that some perf db-export functionality works
as reported in this regression by Ben Gainey <ben.gainey@arm.com>:
https://lore.kernel.org/lkml/20231207140911.3240408-1-ben.gainey@arm.com/

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Ben Gainey <ben.gainey@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20231207174057.1482161-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>