You say that the runtime is disappearing. But, if LLVM is being used, then since it provides the JIT, I'd say it is a really big part of the runtime, actually.
The "VM" in LLVM is deceiving (and LLVM actually no longer stands for "low-level virtual machine"), its main use now is as an ahead-of-time optimiser/code-generator for the Clang C & C++ compiler. Rust uses it in this capacity too: optimised native code is emitted at compile time and no JITing is necessary.
Of course, LLVM can be used as a JIT (e.g. what Apple is doing with javascript), but Rust does not use or need it.
> Of course, LLVM can be used as a JIT (e.g. what Apple is doing with javascript)
Even then, assuming you're talking about FTL LLVM is "just" a codegen backend (w/ optimisations) for an existing JIT pipeline, most of the JIT infrastructure is outside LLVM.
