Temporariy add ASN1_item_verify_ctx() missingcrypto.txt

PR #10942 introduced the new function ASN1_item_verify_ctx(), but did
not document it with the promise that documentation would follow soon.
We temporarily add this function to missingcrypto.txt until it has been
done.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/10980)
1 file changed