[llvm] [Offload] Add support for riscv64 to host plugin (PR #115773)

[via llvm-commits]

joshua-arch1 wrote:

> `libomp` doesn't support RISC-V yet. There is a PR but the author doesn't know whether it works properly or not.

Which PR? 

https://github.com/llvm/llvm-project/pull/115773