Delete blocks from DTU to avoid dangling pointers

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353804 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopSimplifyCFG.cpp b/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
index 896f9dd..5bb6049 100644
--- a/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
+++ b/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
@@ -422,7 +422,7 @@
     DTU.applyUpdates(DTUpdates);
     DTUpdates.clear();
     for (auto *BB : DeadLoopBlocks)
-      BB->eraseFromParent();
+      DTU.deleteBB(BB);
 
     NumLoopBlocksDeleted += DeadLoopBlocks.size();
   }