[clang] [llvm] [AArch64] Improve bcvtn2 and remove aarch64_neon_bfcvt intrinsics (PR #120363)

[David Green via cfe-commits]

davemgreen wrote:

Hi - that sounds like GISel might be miss-compiling it? It doesn't support bf16, so shouldn't be trying to use those instructions for fp16. I can try and take a look.

https://github.com/llvm/llvm-project/pull/120363