[llvm] [RISCV] Remove duplicate WriteRes<WriteJalr for MIPSP8700. (PR #123865)

[Min-Yih Hsu via llvm-commits]

mshockwave wrote:

> Is this something we should enforce in TableGen -- no duplicates allowed?

does #123876 enforce this? Specifically when it's adding new WriteRes into the map.

https://github.com/llvm/llvm-project/pull/123865