LoopRotationUtils: Use initializer list instead of repeated push_back (#139312)

Author: arsenm

llvm/lib/Transforms/Utils/LoopRotationUtils.cpp

@@ -822,10 +822,10 @@ bool LoopRotate::rotateLoop(Loop *L, bool SimplifiedLatch) {
     if (DT) {
       // The OrigPreheader branches to the NewHeader and Exit now. Then, inform
       // the DT about the removed edge to the OrigHeader (that got removed).
-      SmallVector<DominatorTree::UpdateType, 3> Updates;
-      Updates.push_back({DominatorTree::Insert, OrigPreheader, Exit});
-      Updates.push_back({DominatorTree::Insert, OrigPreheader, NewHeader});
-      Updates.push_back({DominatorTree::Delete, OrigPreheader, OrigHeader});
+      SmallVector<DominatorTree::UpdateType, 3> Updates = {
+          {DominatorTree::Insert, OrigPreheader, Exit},
+          {DominatorTree::Insert, OrigPreheader, NewHeader},
+          {DominatorTree::Delete, OrigPreheader, OrigHeader}};
 
       if (MSSAU) {
         MSSAU->applyUpdates(Updates, *DT, /*UpdateDT=*/true);