Use new GCC 13 flags for compilation

New GCC compilation flags might be interesting and added to the compilation process when supported:

-Wenum-int-mismatch warns about mismatches between an enumerated type and an integer type (PR105131)

And in the context of SECURITY_HARDENING flag:

New options -fharden-compares and -fharden-conditional-branches to verify compares and conditional branches, to detect some power-deprivation hardware attacks, using reversed conditions.