[clang] [llvm] [RISC-V] Add support for MIPS P8700 CPU (PR #117865)

[Alex Bradbury via cfe-commits]

asb wrote:


> RFC: https://discourse.llvm.org/t/rfc-risc-v-add-support-for-mips-p8700-cpu/83365

Thank you Djordje - I've left some high level comments in response to your RFC post

https://github.com/llvm/llvm-project/pull/117865