perf cs-etm: Support sample flags 'insn' and 'insnlen'

perf cs-etm: Support sample flags 'insn' and 'insnlen'

The synthetic branch and instruction samples are missed to set
instruction related info, thus the perf tool fails to display samples
with flags '-F,+insn,+insnlen'.

The CoreSight trace decoder provides sufficient information to decide
the instruction size based on the ISA type: A64/A32 instructions are
32-bit size, but one exception is the T32 instruction size, which might
be 32-bit or 16-bit.

This patch handles these cases and it reads the instruction values from
DSO file; thus can support the flags '-F,+insn,+insnlen'.

Before:

  # perf script -F,insn,insnlen,ip,sym
                0 [unknown] ilen: 0
     ffff97174044 _start ilen: 0
     ffff97174938 _dl_start ilen: 0
     ffff97174938 _dl_start ilen: 0
     ffff97174938 _dl_start ilen: 0
     ffff97174938 _dl_start ilen: 0
     ffff97174938 _dl_start ilen: 0
     ffff97174938 _dl_start ilen: 0
     ffff97174938 _dl_start ilen: 0
     ffff97174938 _dl_start ilen: 0

  [...]

After:

  # perf script -F,insn,insnlen,ip,sym
                0 [unknown] ilen: 0
     ffff97174044 _start ilen: 4 insn: 2f 02 00 94
     ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54
     ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54
     ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54
     ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54
     ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54
     ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54
     ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54
     ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54

  [...]

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Robert Walker <robert.walker@arm.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20190815082854.18191-1-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>