159f1c048e
Current implementation uses `std::copy` to shift all incoming values after the removed index. This patch optimizes `PHINode::removeIncomingValue()` by replacing the linear shift of incoming values with a swap-with-last strategy. After this change, the relative order of incoming values after removal is not preserved. This improves compile-time for PHI nodes with many predecessors. Depends: https://github.com/llvm/llvm-project/pull/171955 https://github.com/llvm/llvm-project/pull/171956 https://github.com/llvm/llvm-project/pull/171960 https://github.com/llvm/llvm-project/pull/171962