[llvm] AMDGPU: Add round-to-odd rounding during f64 to bf16 conversion (PR #133995)

[Changpeng Fang via llvm-commits]

changpeng wrote:

> Can you clean up the description to refer to just the changes here, without referring to the out of tree commit context

Okay. Thanks.

https://github.com/llvm/llvm-project/pull/133995