Add a test for read_ahead data crossing a key change
Add a test for read_ahead data crossing a key change

If read_ahead is switched on, it should still work even if the data that
is read cross epochs.

Reviewed-by: Hugo Landau <ce9fa1e55a72fc9b85dd06e47ea2c07848fb7d2c@openssl.org>
Reviewed-by: Tomas Mraz <2bc6038c3dfca09b2da23c8b6da8ba884dc2dcc2@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18132)

openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl