[clang] [RISCV] Disable generation of asynchronous unwind tables for RISCV baremetal (PR #81727)

[Garvit Gupta via cfe-commits]

quic-garvgupt wrote:

Hi @asb, since Petr already gave a good-ahead to this patch in the meeting, let me know if we can merge this PR if there are no new changes need to be made

https://github.com/llvm/llvm-project/pull/81727