[llvm] [LLVM][AMDGPU] AMDGPUInstCombineIntrinsic for *lane intrinsics (PR #99878)

[Sameer Sahasrabuddhe via llvm-commits]

ssahasra wrote:

Is this PR still active? The general direction looks okay to me, but every place that uses UI needs to show why it is _safe_ to continue using UI after each local change to the code.

https://github.com/llvm/llvm-project/pull/99878