Restore implementation of |NETSCAPE_SPKI_verify|.

Change-Id: I42c185a47af7e96e000ec1704e046b33a8571d1e
Reviewed-on: https://boringssl-review.googlesource.com/5153
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/crypto/x509/x_all.c b/crypto/x509/x_all.c
index 785fd1e..32faa55 100644
--- a/crypto/x509/x_all.c
+++ b/crypto/x509/x_all.c
@@ -144,6 +144,12 @@
 		x->signature, x->spkac,pkey,md));
 	}
 
+int NETSCAPE_SPKI_verify(NETSCAPE_SPKI *x, EVP_PKEY *pkey)
+	{
+	return (ASN1_item_verify(ASN1_ITEM_rptr(NETSCAPE_SPKAC), x->sig_algor,
+		x->signature, x->spkac, pkey));
+	}
+
 #ifndef OPENSSL_NO_FP_API
 X509 *d2i_X509_fp(FILE *fp, X509 **x509)
 	{