[clang] [llvm] [RISCV] Add Smcsrind and Sscsrind extension (PR #93952)

[Yingwei Zheng via cfe-commits]

https://github.com/dtcxzyw commented:

Can you also update `llvm/docs/ReleaseNotes.rst` ?


https://github.com/llvm/llvm-project/pull/93952