Set the 'MadeChange' variable if we are deleting blocks.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169455 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Scalar/CodeGenPrepare.cpp

@@ -195,6 +195,7 @@ bool CodeGenPrepare::runOnFunction(Function &F) {
     }
 
     // Delete the dead blocks and any of their dead successors.
+    MadeChange |= !WorkList.empty();
     while (!WorkList.empty()) {
       BasicBlock *BB = *WorkList.begin();
       WorkList.erase(BB);