Loop Rotation pass preserves dominator tree and frontier.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40603 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Scalar/LoopRotation.cpp

@@ -62,6 +62,8 @@ namespace {
       AU.addPreserved<LoopInfo>();
       AU.addRequiredID(LoopSimplifyID);
       AU.addPreservedID(LoopSimplifyID);
+      AU.addPreserved<DominatorTree>();
+      AU.addPreserved<DominanceFrontier>();
     }
 
     // Helper functions