Add test cases for RNDR and RNDRRS. Combine tests for RDRAND and RNDR to
share common logic.
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/15361)
(cherry picked from commit 1f8ce0c9fa)