There is a proposal[1] to upgrade the current EVM to a WebAssembly based VM. Since webAssembly has a llvm backend, any language with a llvm compiler (which is most of them) could be used to write contract code.
A programming language is a combination of many components; assembly optimization and target code generation is just one important part of a much larger picture.
I'm only responding critically because I've seen this trope that LLVM is some sort of universal programming language target way too often now. It misleads people into underestimating the scope of the actual problem. LLVM is not a panacea.
If you really want to make your platform programmable from any programming language, invest time into a well designed C API. Your users will thank you.
1. https://github.com/ethereum/EIPs/issues/48#issuecomment-1690...