consider using Hardened Malloc

[Florian Weimer]

* Patrick Schleizer:

> https://github.com/GrapheneOS/hardened_malloc

It's 64-bit only, so it's non-starter in its current form.  It also
seems to require a large vm.max_map_count value, and that would have to
be addressed as well.  I don't know how feasible that is in practice.

I couldn't find any performance comparisons with other hardended
allocators (such as Scudo).

Thanks,
Florian