Test EVP_CipherInit sequences and resets
Test EVP_CipherInit sequences and resets

Various EVP_CipherInit sequences including partial inits and initializations
with different "enc" flags caused problems on s390x.  Similarly, cipher
reinitialization and especially GCM reinitialization with different tag length
led to wrong results.  Add some unit tests to cover these rather exotic use
cases.

Signed-off-by: Juergen Christ <jchrist@linux.ibm.com>

Reviewed-by: Tomas Mraz <2bc6038c3dfca09b2da23c8b6da8ba884dc2dcc2@openssl.org>
Reviewed-by: Paul Dale <ddec78389666b4f7c9b4d110380c848489a3e4aa@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/15521)

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