You don't have a version of rpcs3 that has the llvm compiler integrated. Either build it yourself or get a version that has llvm included.
The builds automatically posted here don't include the llvm libs, because it depends on cmake and python and whoever setup the build-server didn't install cmake and python or just chose not to build the llvm versions.
The builds automatically posted here don't include the llvm libs, because it depends on cmake and python and whoever setup the build-server didn't install cmake and python or just chose not to build the llvm versions.