Extend the threads test to add simple fetch from multi threads
Extend the threads test to add simple fetch from multi threads

Issue #13682 suggests that doing a simple fetch from multi-threads may
result in issues so we add a test for that.

Reviewed-by: Tomas Mraz <973cc78d8b4cb00714230ba9be0225e917ab4ac6@fedoraproject.org>
(Merged from https://github.com/openssl/openssl/pull/13660)

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