Make it clear that this code is iterating in reverse order through the array.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137985 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/ObjCARC.cpp b/lib/Transforms/Scalar/ObjCARC.cpp
index c74c353..5e878cf 100644
--- a/lib/Transforms/Scalar/ObjCARC.cpp
+++ b/lib/Transforms/Scalar/ObjCARC.cpp
@@ -2596,8 +2596,9 @@
     Order.push_back(Stack.pop_back_val().first);
   }
   bool BottomUpNestingDetected = false;
-  while (!Order.empty()) {
-    BasicBlock *BB = Order.pop_back_val();
+  for (SmallVectorImpl<BasicBlock *>::const_reverse_iterator I =
+         Order.rbegin(), E = Order.rend(); I != E; ++I) {
+    BasicBlock *BB = *I;
     BottomUpNestingDetected |= VisitBottomUp(BB, BBStates, Retains);
   }