perf symbols: Record whether a symbol is an alias for an IFUNC symbol

To assist with synthesizing plt symbols for IFUNCs, record whether a
symbol is an alias of an IFUNC symbol.

Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230131131625.6964-5-adrian.hunter@intel.com


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