llvm9 branch will be merged into master today (as soon as the CI infrastructure is updated with LLVM 9) and it has basic risc-v support in the std lib, as well

llvm9 branch will be merged into master today (as soon as the CI infrastructure is updated with LLVM 9) and it has basic risc-v support in the std lib, as well as cross compilation targeting risc-v using glibc and musl. edit: [me updating the CI infrastructure](https://twitter.com/andy_kelley/status/1174769700343074818 https://twitter.com/andy_kelley/status/1174769700343074818)