do not rely on the implicit-dereference semantics of dyn_cast_or_null

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114278 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index e8dc5d3..fca7bae 100644
--- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -608,7 +608,7 @@
   bool Changed = false;
 
   while (!DeadInsts.empty()) {
-    Instruction *I = dyn_cast_or_null<Instruction>(DeadInsts.pop_back_val());
+    Instruction *I = dyn_cast_or_null<Instruction>(&*DeadInsts.pop_back_val());
 
     if (I == 0 || !isInstructionTriviallyDead(I))
       continue;