That was possible before when targeting RV32. If I understand correctly, this makes it possible for LLVM to use all RISC-V extensions supported by the core with a simple command line (the patch describes what features the core supports), resulting in better-optimized code.
However, to run any language on the Pi Pico, that language still needs to interop with Pico's SDK, which you'd have to do manually if no one created bindings yet.
However, to run any language on the Pi Pico, that language still needs to interop with Pico's SDK, which you'd have to do manually if no one created bindings yet.