There's an ongoing effort to create a Clang/LLVM implementation of Clojure's runtime with hot reloading and other very interesting features. You can take a look at it at https://jank-lang.org/. It still hasn't reached feature parity with full blown JVM Clojure but we've paying close attention to its development.

the top comment as of writing this reply points to https://babashka.org/, but it's GraalVM instead of LLVM (which shouldn't really bother you)

Babashka scripts are interpreted, the babashka binary itself is compiled with GraalVM.

But: you can also build regular Clojure programs using GraalVM and create a fast-starting binary.

Soon there will be! https://jank-lang.org

Do they have a realistic shot at implementing immutable datastructures?

Oh for sure. That's not the tough part. :)

jank uses immer for that: https://github.com/arximboldi/immer