util/other-internal.syms is like util/other.syms, but for internal symbols.
Likewise, util/missingcrypto-internal.txt and util/missingssl-internal.txt
are like util/missingcrypto.txt and util/missingssl.txt
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/11476)
