perf intel-pt: decoder: Add MODE.Exec IFLAG processing

perf intel-pt: decoder: Add MODE.Exec IFLAG processing

As of Intel SDM (https://www.intel.com/sdm) version 076, there is a new
Intel PT feature called Event Trace which adds a bit to the existing
MODE.Exec packet to record the interrupt flag.

Previously, the MODE.Exec packet did not generate any events, so the
new processing required is practically the same as a new packet.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20220124084201.2699795-9-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>