> When this happens, it seems like it'll be possible to get the LLVM bits out of the bootstrap process and lead to a fully self-hosted Rust.
What do you mean by "when this happens"? GP's point is that this has already happened: the Cranelift backend is feature-complete from the perspective of the language [0], except for inline assembly and unwinding on panic. It was merged into the upstream compiler in 2020 [1], and a Cranelift-based Rust compiler is perfectly capable of bootstrapping another Rust compiler (with some config changes) [2].
What do you mean by "when this happens"? GP's point is that this has already happened: the Cranelift backend is feature-complete from the perspective of the language [0], except for inline assembly and unwinding on panic. It was merged into the upstream compiler in 2020 [1], and a Cranelift-based Rust compiler is perfectly capable of bootstrapping another Rust compiler (with some config changes) [2].
[0] https://github.com/bjorn3/rustc_codegen_cranelift
[1] https://github.com/rust-lang/rust/pull/77975
[2] https://github.com/bjorn3/rustc_codegen_cranelift/actions/ru...