perf tools: Add stat round event synthesize function

Introduce the perf_event__synthesize_stat_round function to
synthesize a 'struct stat_round_event'.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Kan Liang <kan.liang@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1445784728-21732-19-git-send-email-jolsa@kernel.org
[ Renamed 'time' parameter to 'evtime' to fix build on older systems ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/tests.h

@@ -83,6 +83,7 @@ int test__thread_map_synthesize(int subtest);
 int test__cpu_map_synthesize(int subtest);
 int test__synthesize_stat_config(int subtest);
 int test__synthesize_stat(int subtest);
+int test__synthesize_stat_round(int subtest);
 
 #if defined(__arm__) || defined(__aarch64__)
 #ifdef HAVE_DWARF_UNWIND_SUPPORT