libbeauty: Add a strarray__scnprintf_suffix() method

In some cases, like with x86 IRQ vectors, the common part in names is at
the end, so a suffix, add a scnprintf function for that.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-agxbj6es2ke3rehwt4gkdw23@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 907eaf3..58bbe85 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -423,6 +423,20 @@ static struct evsel *perf_evsel__raw_syscall_newtp(const char *direction, void *
 	({ struct syscall_tp *fields = evsel->priv; \
 	   fields->name.pointer(&fields->name, sample); })
 
+size_t strarray__scnprintf_suffix(struct strarray *sa, char *bf, size_t size, const char *intfmt, bool show_suffix, int val)
+{
+	int idx = val - sa->offset;
+
+	if (idx < 0 || idx >= sa->nr_entries || sa->entries[idx] == NULL) {
+		size_t printed = scnprintf(bf, size, intfmt, val);
+		if (show_suffix)
+			printed += scnprintf(bf + printed, size - printed, " /* %s??? */", sa->prefix);
+		return printed;
+	}
+
+	return scnprintf(bf, size, "%s%s", sa->entries[idx], show_suffix ? sa->prefix : "");
+}
+
 size_t strarray__scnprintf(struct strarray *sa, char *bf, size_t size, const char *intfmt, bool show_prefix, int val)
 {
 	int idx = val - sa->offset;