perf tests: Skip record test if test_loop symbol is missing

perf tests: Skip record test if test_loop symbol is missing

perf record test depends on finding symbol test_loop in perf, and fails if
perf has been stripped and no debug object is available. In that case, skip
the test instead.

Example:

 Note, building with perl support adds option -Wl,-E which causes the
 linker to add all (global) symbols to the dynamic symbol table. So the
 test_loop symbol, being global, does not get stripped unless NO_LIBPERL=1

 Before:

  $ make NO_LIBPERL=1 -C tools/perf >/dev/null 2>&1
  $ strip tools/perf/perf
  $ tools/perf/perf buildid-cache -p `realpath tools/perf/perf`
  $ tools/perf/perf test -v 'record tests'
   91: perf record tests                                               :
  --- start ---
  test child forked, pid 118750
  Basic --per-thread mode test
  Per-thread record [Failed missing output]
  Register capture test
  Register capture test [Success]
  Basic --system-wide mode test
  System-wide record [Skipped not supported]
  Basic target workload test
  Workload record [Failed missing output]
  test child finished with -1
  ---- end ----
  perf record tests: FAILED!

 After:

  $ tools/perf/perf test -v 'record tests'
   91: perf record tests                                               :
  --- start ---
  test child forked, pid 120025
  perf does not have symbol 'test_loop'
  perf is missing symbols - skipping test
  test child finished with -2
  ---- end ----
  perf record tests: Skip

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20231123075848.9652-5-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>