perf probe: Add test for regression introduced by switch to die_get_decl_file()

perf probe: Add test for regression introduced by switch to die_get_decl_file()

This patch adds a test to validate that 'perf probe' works for binaries
where DWARF info is split into multiple CUs

Signed-off-by: Georg Müller <georgmueller@gmx.net>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: regressions@lists.linux.dev
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230628084551.1860532-5-georgmueller@gmx.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>