Adding a new test vector.

https://github.com/google/tink/issues/224
So far I haven't been able to reproduce the bug.
However, a lot of tests just check the signature verification.

NOKEYCHECK=True
PiperOrigin-RevId: 260466789
GitOrigin-RevId: bc252d53eaede4ec4eb89fef072dc5d19d17dbf5

testvectors/eddsa_test.json

@@ -1,7 +1,7 @@
 {
   "algorithm" : "EDDSA",
-  "generatorVersion" : "0.7",
-  "numberOfTests" : 111,
+  "generatorVersion" : "0.8r8",
+  "numberOfTests" : 112,
   "header" : [
     "Test vectors of type EddsaVerify are intended for testing",
     "the verification of Eddsa signatures."
@@ -1271,6 +1271,35 @@
           "flags" : []
         }
       ]
+    },
+    {
+      "jwk" : {
+        "crv" : "Ed25519",
+        "d" : "EvwxxA1aevceBUJGI7qXC2cM9uy0TNphICEOY3AkXds",
+        "kid" : "none",
+        "kty" : "OKP",
+        "x" : "A3tVtCfcjaoPgPzrrwhGkCMJ-KbPGLRlwM6bZTlimsg"
+      },
+      "key" : {
+        "curve" : "edwards25519",
+        "keySize" : 255,
+        "pk" : "037b55b427dc8daa0f80fcebaf0846902309f8a6cf18b465c0ce9b6539629ac8",
+        "sk" : "12fc31c40d5a7af71e05424623ba970b670cf6ecb44cda6120210e6370245ddb",
+        "type" : "EDDSAKeyPair"
+      },
+      "keyDer" : "302a300506032b6570032100037b55b427dc8daa0f80fcebaf0846902309f8a6cf18b465c0ce9b6539629ac8",
+      "keyPem" : "-----BEGIN PUBLIC KEY-----\nMCowBQYDK2VwAyEAA3tVtCfcjaoPgPzrrwhGkCMJ+KbPGLRlwM6bZTlimsg=\n-----END PUBLIC KEY-----\n",
+      "type" : "EddsaVerify",
+      "tests" : [
+        {
+          "tcId" : 112,
+          "comment" : "https://github.com/google/tink/issues/224",
+          "msg" : "01234567",
+          "sig" : "c964e100033ce8888b23466677da4f4aea29923f642ae508f9d0888d788150636ab9b2c3765e91bbb05153801114d9e52dc700df377212222bb766be4b8c020d",
+          "result" : "valid",
+          "flags" : []
+        }
+      ]
     }
   ]
 }