perf scripting python: Add perf_sample_srcline() and perf_sample_srccode()

Add perf_sample_srcline() and perf_sample_srccode() to the
perf_trace_context module so that a script can get the srcline or srccode
information.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20210530192308.7382-11-adrian.hunter@intel.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>