perf tools: Add Intel PT support for decoding TRACESTOP packets

perf tools: Add Intel PT support for decoding TRACESTOP packets

A TRACESTOP packet is produced when an Intel PT trace enters a defined
region of the address space at which point the tracing stops.

This patch just adds decoder support.

Support for specifying TRACESTOP regions is left until later.

For details refer to the June 2015 or later Intel 64 and IA-32
Architectures SDM Chapter 36 Intel Processor Trace.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1437150840-31811-25-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>