[clang] [llvm] [KCFI][NFC] Rename the !kcfi_type Function metadata to !cfi_type (PR #109080)

[Ming-Yi Lai via cfe-commits]

mylai-mtk wrote:

@MaskRay Sure, I also agree that `!cfi_type` is a too general name and covers too little possibility for its name. I picked this approach instead of adding RISC-V-specific metadata nodes just to avoid adding RISC-V specifics to the conceptually backend-neutral LLVM IR. However, if this approach looks too general, maybe it's better to just use RISC-V-specific metadata nodes.
(I'm closing this PR then, since it's not a good idea.)

https://github.com/llvm/llvm-project/pull/109080