perf annotate: Merge same lines in summary view

perf annotate: Merge same lines in summary view

The --print-line option of perf annotate command shows summary for
each source line.  But it didn't merge same lines so that it can
appear multiple times.

* before:

  Sorted summary for file /home/namhyung/bin/mcol
  ----------------------------------------------
     21.71 /home/namhyung/tmp/mcol.c:26
     20.66 /home/namhyung/tmp/mcol.c:25
      9.53 /home/namhyung/tmp/mcol.c:24
      7.68 /home/namhyung/tmp/mcol.c:25
      7.67 /home/namhyung/tmp/mcol.c:25
      7.66 /home/namhyung/tmp/mcol.c:26
      7.49 /home/namhyung/tmp/mcol.c:26
      6.92 /home/namhyung/tmp/mcol.c:25
      6.81 /home/namhyung/tmp/mcol.c:25
      1.07 /home/namhyung/tmp/mcol.c:26
      0.52 /home/namhyung/tmp/mcol.c:25
      0.51 /home/namhyung/tmp/mcol.c:25
      0.51 /home/namhyung/tmp/mcol.c:24

* after:

  Sorted summary for file /home/namhyung/bin/mcol
  ----------------------------------------------
     50.77 /home/namhyung/tmp/mcol.c:25
     37.94 /home/namhyung/tmp/mcol.c:26
     10.04 /home/namhyung/tmp/mcol.c:24

To do that, introduce percent_sum field so that the normal
line-by-line output doesn't get changed.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1352440729-21848-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>