perf tools: Add more weak libbpf functions

We hit the window where perf uses libbpf functions, that did not make it
to the official libbpf release yet and it's breaking perf build with
dynamicly linked libbpf.

Fixing this by providing the new interface as weak functions which calls
the original libbpf functions. Fortunatelly the changes were just
renames.

Signed-off-by: Jiri Olsa <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Andrii Nakryiko <[e-mail]>
Cc: Ian Rogers <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Michael Petlan <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Link: http://lore.kernel.org/lkml/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/bpf-event.c

···
        return err ? ERR_PTR(err) : btf;
 }
 
+struct bpf_program * __weak
+bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prev)
+{
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+	return bpf_program__next(prev, obj);
+#pragma GCC diagnostic pop
+}
+
+struct bpf_map * __weak
+bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *prev)
+{
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+	return bpf_map__next(prev, obj);
+#pragma GCC diagnostic pop
+}
+
+const void * __weak
+btf__raw_data(const struct btf *btf_ro, __u32 *size)
+{
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+	return btf__get_raw_data(btf_ro, size);
+#pragma GCC diagnostic pop
+}
+
 static int snprintf_hex(char *buf, size_t size, unsigned char *data, size_t len)
 {
 	int ret = 0;