[llvm] [RISCV][Disassemble] Ensure the comment stream of the disassembler is set. (PR #125962)

[via llvm-commits]

tedwoodward wrote:

> Maybe we just need to set the comment stream in HexagonDisassembler::getInstruction?

I'm talking to our guys internally about that; but there are other cores out there that will need to do the same thing.

https://github.com/llvm/llvm-project/pull/125962