BUG/MINOR: pools/threads: don't ignore DEBUG_UAF on double-word CAS capable archs

BUG/MINOR: pools/threads: don't ignore DEBUG_UAF on double-word CAS capable archs

Since commit cf975d4 ("MINOR: pools/threads: Implement lockless memory
pools."), we support lockless pools. However the parts dedicated to
detecting use-after-free are not present in this part, making DEBUG_UAF
useless in this situation.

The present patch sets a new define CONFIG_HAP_LOCKLESS_POOLS when such
a compatible architecture is detected, and when pool debugging is not
requested, then makes use of this everywhere in pools and buffers
functions. This way enabling DEBUG_UAF will automatically disable the
lockless version.

No backport is needed as this is purely 1.9-dev.