Ensure we build ub sanitizer builds with -DPEDANTIC

Ensure we build ub sanitizer builds with -DPEDANTIC

Otherwise we may get spurious results from ub sanitizer. For example we
assume we can tolerate some unaligned write without this define that ub
sanitizer will complain about.

Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Hugo Landau <hlandau@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18983)

(cherry picked from commit 17b94de3df327e6619e52529e345a340d4a0a100)