Options for a new global allocator implementation.

[pantsman0]

Phil Opp's linked list allocator is broken on nightly and there is seemingly no rush to resolve the build error.

We need some options about of we fork and patch the allocator create, or of we migrate to another no_std allocator create.

[sermuns]

• rcore-os/buddy_system_allocator markets itself as (almost) drop-in replacement for phil-opp/linked-list-allocator.
• rust-embedded/embedded-alloc seems to be the most well-established allocator for embedded systems.

[pantsman0]

buddy_system_allocator does sound nice, but if we're talking long term stability then using an allocator from the rust embedded working group would be great.

It seems relatively easy to use too, though it needs a critical section implementation. Here's a rough attempt, though I haven't tested the examples with it yet as I've just moved house and haven't unpacked my switches yet.
https://github.com/aarch64-switch-rs/nx/tree/new_allocator