This queries the provider for its available functionality (unless a
matching method structured is already cached, in which case that's
used instead), and creates method structure with the help of a passed
constructor. The result is cached if the provider allows it (or if
caching is forced).
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/8340)
Richard Levitte