perf tools: Add 'G' and 'H' modifiers to event parsing

They were dropped during conversion of event parser. Add test case to
make sure this will not happen again.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20120417111345.GK11918@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>