> I really can't see Linus and others being okay with any GCC
> plugins with alterations to the semantics of C rather than just codegen
> like the KERNEXEC plugin.

Oh and REFCOUNT is basically the same situation. I can't see any
possibility of that landing without switching to having a refcount_t
type and having separate functions for working with it, with a
configuration option like DEBUG_REFCOUNT to flip on overflow checks.
It's a whole bunch of busy-work and since it will touch so much code it
will run into the same problems that the previous attempts to upstream
constification did.