PS: Feel free to move the IMPLEMENT_STACK_OF(X509_INFO) from
crypto/asn1/x_info.c to any other place where you think it fits better.
X509_INFO is a structure slightly spreaded over ASN.1, X509 and PEM code,
so I found no definitive location for IMPLEMENT_STACK_OF(X509_INFO). In
crypto/asn1/x_info.c it's at least now bundled with X509_INFO_new() and
friends.