[llvm] [AMDGPU] Support function attribute to override postRA scheduling direction (PR #147708)

[Harrison Hao via llvm-commits]

harrisonGPU wrote:

> Missing tests and I thought there already was an attribute for this

No, we don’t have this attribute. I’ve hit this issue, the current option only applies to the whole pipeline, not per shader stage. Also, I’m not sure how to write a lit test for this , what exactly should test check?

https://github.com/llvm/llvm-project/pull/147708