Merge branches 'feature/linux-hardened', 'feature/lockdown' and 'reve…

…rts'

In this new major kernel version, we drop 'feature/stackleak' which was
extending upstream's STACKLEAK with alloca() calls checking
(7a94313 - "stackleak: reintroduce checking of alloca() calls").
The rationale described at that time was:
    - act as a failsafe, for instance if VLAs were to be inadvertently
    reintroduced: this should not happen now that -Wvla is used;
    - protect out-of-tree code: likewise, plus we control such code.

Change-Id: I99b386055f97a1827d7b5461ffbf04604d062d7e
Signed-off-by: Thibaut Sautereau <thibaut.sautereau@ssi.gouv.fr>