Update NSPR to 4.12 and NSS to 3.23 on iOS

nss/lib/softoken/pkcs11i.h

Index: nss/lib/softoken/pkcs11i.h
diff --git a/nss/lib/softoken/pkcs11i.h b/nss/lib/softoken/pkcs11i.h
index 4e8601b5a14877395ffac6919eb15dfca5517949..8f16357cecbe03317821cece0f197cfa217c184d 100644
--- a/nss/lib/softoken/pkcs11i.h
+++ b/nss/lib/softoken/pkcs11i.h
@@ -401,11 +401,11 @@ struct SFTKSSLMACInfoStr {
     unsigned int	keySize;
 };
 
-/* SFTKChaCha20Poly1305Info saves the key, tag length, nonce, and additional
- * data for a ChaCha20+Poly1305 AEAD operation. */
+/* SFTKChaCha20Poly1305Info saves the key, tag length, nonce,
+ * and additional data for a ChaCha20+Poly1305 AEAD operation. */
 struct SFTKChaCha20Poly1305InfoStr {
     ChaCha20Poly1305Context freeblCtx;
-    unsigned char nonce[8];
+    unsigned char nonce[12];
     unsigned char ad[16];
     unsigned char *adOverflow;
     unsigned int adLen;