[clang] [llvm] Revert "[RISCV] Remove B and Zbc extension from Andes series cpus." (PR #144402)

[Sam Elliott via llvm-commits]

lenary wrote:

We probably need to file an infrastructure ticket to get to the bottom of this issue. I've seen the same issues @mshockwave has seen.

https://github.com/llvm/llvm-project/pull/144402