Support official Rust FFI bindings

[OscarTHZhang]

Currently the most popular mimalloc Rust wrapper is https://github.com/purpleprotocol/mimalloc_rust, but it only exposes mimalloc as a global allocator and all the rich features such as Arenas are missing or only available in the hidden libmimalloc-sys crate. The mimalloc version is also not up-to-date.

There are also other open-source projects building the mimalloc Rust FFI bindings themselves. An example of this is Bun: https://github.com/oven-sh/bun, where it mirrored the mimalloc source code and build a thin FFI layer itself.

It'd be good for the mimalloc to release its official Rust FFI bindings so that all the APIs, documentation, and bug fixes are up to date, just like how ms-quic has a core C implementation and at the same time expose its APIs to C++/C#/Rust: https://github.com/microsoft/msquic

[daanx]

Yes, it would be nice to have a rust wrapper as part of mimalloc; also to ensure we get the best performance. I am not a Rust expert though but I will consider PR's (to dev3) in the contrib directory (much like the vcpkg one) that are clean and not too complex. I am not sure we want to be in the business of distributing crate's etc. but providing a basic wrapper would be good for any downstream crate. (no pressure on you OscarTHZhang -- I meant at in general to people that may be interested in this; I am also looking for a vcpkg maintainer :-) )