[VPlan] Remove ILV::sinkScalarOperands.

[fhahn]

Remove legacy ILV sinkScalarOperands, which is superseded by the sinkScalarOperands VPlan transforms.

There are a few cases that aren't handled by VPlan's sinkScalarOperands, namely when we have scalar-steps where the first lane is used outside a replicate region; the IR-based sinking is able to sink computing the steps for all lanes except the first.

We could improve this further, by duplicating such scalar-steps recipes, one to serve the first-lane-only users and users in replicate regions, but I am not sure if the extra complexity is warrented.

[github-actions]

⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️

You can test this locally with the following command:

git-clang-format --diff HEAD~1 HEAD --extensions cpp -- llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

View the diff from clang-format here.

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index d2f93bb7d..586a66af6 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -2857,7 +2857,6 @@ void InnerLoopVectorizer::fixVectorizedLoop(VPTransformState &State) {
   if (!State.Plan->getVectorLoopRegion())
     return;
 
-
   VPRegionBlock *VectorRegion = State.Plan->getVectorLoopRegion();
   VPBasicBlock *HeaderVPBB = VectorRegion->getEntryBasicBlock();
   BasicBlock *HeaderBB = State.CFG.VPBB2IRBB[HeaderVPBB];