perf stat: Add id into perf_stat struct

perf stat: Add id into perf_stat struct

We need fast way to identify evsel as transaction event for shadow
counters computation. Currently we are using possition (in evlist) based
way.

Adding 'id' into 'struct perf_stat' so it can carry transaction event ID
and we can use it for shadow counters computations.

Signed-off-by: Jiri Olsa <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>