Is anyone able to build libcxx/libcxxabi for riscv

Hello, as described in How to build libcxx/libcxxabi for riscv target, I tried to build libcxx/libcxxabi using clang for riscv, but met a lot of error described in this link, did anyone able to build libcxx/libcxxabi for riscv target, could you give me some guidance.

And by the way, another question is about multilib support in clang seems not as good as gcc does, which support MULTILIB_REUSE but clang only support one arch, one library folder, is there any plan to support it in clang or some better solution?

Thanks