perf tools: Dump callchain context marker names

perf tools: Dump callchain context marker names

These are hard to interpret in the raw output because they are printed
as hex but are defined in perf_event.h as decimal. Make it much easier
to read the raw callchains by just printing their names.

For example:

  $ perf report -D

  1798195372321 0x4638 [0xb0]: PERF_RECORD_SAMPLE(IP, 0x4002): 44922/44922: 0x7c8046dd3400 period: 120218 addr: 0
  ... FP chain: nr:12
  .....  0: fffffffffffffe00 (PERF_CONTEXT_USER)
  .....  1: 00007c8046dd3400
  .....  2: 00007c8046db86d3

Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
[ Add PERF_CONTEXT_USER_DEFERRED too, as per Namhyung's review comment ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>