The --skip-empty option is to hide dummy events in a group.  Like other
output mode in 'perf report' and 'perf annotate', the data-type
profiling output should support the option.

Committer testing:

With dummy:

  root@number:~# perf annotate --stdio --group --data-type --skip-empty | head -24
  Annotate type: 'pthread_mutex_t' in /usr/lib64/libc.so.6 (50 samples):
   event[0] = cpu_atom/mem-loads,ldlat=30/P
   event[1] = cpu_atom/mem-stores/P
   event[2] = dummy:u
  ============================================================================
                   Percent     offset       size  field
    100.00  100.00    0.00          0         40  pthread_mutex_t	 {
    100.00  100.00    0.00          0         40      struct __pthread_mutex_s	__data {
     45.21   84.54    0.00          0          4          int	__lock;
      0.00    0.00    0.00          4          4          unsigned int	__count;
      0.00    1.83    0.00          8          4          int	__owner;
      5.19   10.65    0.00         12          4          unsigned int	__nusers;
     49.61    2.97    0.00         16          4          int	__kind;
      0.00    0.00    0.00         20          2          short int	__spins;
      0.00    0.00    0.00         22          2          short int	__elision;
      0.00    0.00    0.00         24         16          __pthread_list_t	__list {
      0.00    0.00    0.00         24          8              struct __pthread_internal_list*	__prev;
      0.00    0.00    0.00         32          8              struct __pthread_internal_list*	__next;
                                                          };
                                                      };
      0.00    0.00    0.00          0          0      char[]	__size;
     45.21   84.54    0.00          0          8      long int	__align;
                                                };
Skipping it:

  root@number:~# perf annotate --stdio --group --data-type --skip-empty | head -24
  Annotate type: 'pthread_mutex_t' in /usr/lib64/libc.so.6 (50 samples):
   event[0] = cpu_atom/mem-loads,ldlat=30/P
   event[1] = cpu_atom/mem-stores/P
  ============================================================================
           Percent     offset       size  field
    100.00  100.00          0         40  pthread_mutex_t	 {
    100.00  100.00          0         40      struct __pthread_mutex_s	__data {
     45.21   84.54          0          4          int	__lock;
      0.00    0.00          4          4          unsigned int	__count;
      0.00    1.83          8          4          int	__owner;
      5.19   10.65         12          4          unsigned int	__nusers;
     49.61    2.97         16          4          int	__kind;
      0.00    0.00         20          2          short int	__spins;
      0.00    0.00         22          2          short int	__elision;
      0.00    0.00         24         16          __pthread_list_t	__list {
      0.00    0.00         24          8              struct __pthread_internal_list*	__prev;
      0.00    0.00         32          8              struct __pthread_internal_list*	__next;
                                                  };
                                              };
      0.00    0.00          0          0      char[]	__size;
     45.21   84.54          0          8      long int	__align;
                                          };

  Annotate type: 'pthread_mutexattr_t' in /usr/lib64/libc.so.6 (1 samples):
  root@number:~#
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240807061713.1642924-1-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>