perf script: Add support to display lost events

perf script: Add support to display lost events

Adding option to display lost events:

  $ perf script --show-lost-events ...
   mplayer 13810 [002] 468011.402396:        100 cycles:ppp:  ff..
   mplayer 13810 [002] 468011.402396: PERF_RECORD_LOST lost 3880
   mplayer 13810 [002] 468011.402397:        100 cycles:ppp:  ff..

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180107160356.28203-10-jolsa@kernel.org
[ Use PRIu64 when printing u64 values, fixing the build in some arches ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>