Committing to Rust for kernel code

I just opened a thread on the Zulip to talk about this. Conan doesn't have too much visibility into the actual work going into our downstream branch Rust support, but I do. And indeed, the biggest problem is 100% upstream: it's the `alloc` crate. That's what is breaking with almost every compiler version bump, and I haven't seen any discussion or plans for how that will be resolved yet.

Upstreaming, the small handful of features used in the other crates, etc. are all things with solid plans going forward, and I look forward to the future for Rust for Linux. But as long as `alloc` is using 100+ unstable features directly upstream, all the work to eventually drop the dozen features used in the `kernel` crate is rather useless. Being able to unpin the Rust compiler version is very important for distros to start taking this seriously and reduce friction enabling Rust support, so I hope there is some plan to eventually solve this. Maybe there is and I just haven't found it? Would be happy to hear your thoughts :)