[C++] Use 'nullptr'. Transforms edition.

llvm-svn: 207196
diff --git a/llvm/lib/Transforms/Scalar/ConstantProp.cpp b/llvm/lib/Transforms/Scalar/ConstantProp.cpp
index 7a0c556..dd51ce1 100644
--- a/llvm/lib/Transforms/Scalar/ConstantProp.cpp
+++ b/llvm/lib/Transforms/Scalar/ConstantProp.cpp
@@ -69,7 +69,7 @@
   }
   bool Changed = false;
   DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
-  const DataLayout *DL = DLP ? &DLP->getDataLayout() : 0;
+  const DataLayout *DL = DLP ? &DLP->getDataLayout() : nullptr;
   TargetLibraryInfo *TLI = &getAnalysis<TargetLibraryInfo>();
 
   while (!WorkList.empty()) {