[llvm] [PowerPC] clean unused PPC target feature FeatureBPERMD (PR #159782)

[Aiden Grossman via llvm-commits]

boomanaiden154 wrote:

> Or did it not? The checks were red and became green after updating a branch, but the merge update didn't trigger all checks

They're definitely showing up as red for me at the time of merge.

<img width="887" height="393" alt="image" src="https://github.com/user-attachments/assets/2112b227-a4c1-4953-9624-e743e69f0b32" />


https://github.com/llvm/llvm-project/pull/159782