t/helper: merge test-index-version into test-tool

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/helper/test-tool.c

@@ -18,6 +18,7 @@ static struct test_cmd cmds[] = {
 	{ "example-decorate", cmd__example_decorate },
 	{ "genrandom", cmd__genrandom },
 	{ "hashmap", cmd__hashmap },
+	{ "index-version", cmd__index_version },
 	{ "lazy-init-name-hash", cmd__lazy_init_name_hash },
 	{ "sha1", cmd__sha1 },
 };