perf script: Support total cycles count

perf script: Support total cycles count

For 'perf script' brstackinsn also print a running cycles count.  This
makes it easier to calculate cycle deltas for code sections measured
with LBRs.

% perf record -b -a sleep 1
% perf script -F +brstackinsn
...
        00007f73ecc41083        insn: 74 06                     # PRED 9 cycles [17] 1.11 IPC
        00007f73ecc4108b        insn: a8 10
        00007f73ecc4108d        insn: 74 71                     # PRED 1 cycles [18] 1.00 IPC
        00007f73ecc41100        insn: 48 8b 46 10
        00007f73ecc41104        insn: 4c 8b 38
        00007f73ecc41107        insn: 4d 85 ff
        00007f73ecc4110a        insn: 0f 84 b0 00 00 00
        00007f73ecc41110        insn: 83 43 58 01
        00007f73ecc41114        insn: 48 89 df
        00007f73ecc41117        insn: e8 94 73 04 00            # PRED 6 cycles [24] 1.00 IPC

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Link: http://lkml.kernel.org/r/20180924170732.GA28040@tassilo.jf.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>