[llvm] [AMDGPU][GlobalISel] Add register bank legalization for buffer_load byte and short (PR #167798)

[Aiden Grossman via llvm-commits]

boomanaiden154 wrote:

I've revert this in b8816a4e833ede66dc365a55a4913406ce4f2ce4 due to the breakage and the seeming lack of a forward fix in the last ~30 minutes. Sorry for the inconvenince.

https://github.com/llvm/llvm-project/pull/167798