[C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr.

llvm-svn: 206243
diff --git a/llvm/lib/Analysis/AliasAnalysis.cpp b/llvm/lib/Analysis/AliasAnalysis.cpp
index 9583bbe..57237e5 100644
--- a/llvm/lib/Analysis/AliasAnalysis.cpp
+++ b/llvm/lib/Analysis/AliasAnalysis.cpp
@@ -473,7 +473,7 @@
 ///
 void AliasAnalysis::InitializeAliasAnalysis(Pass *P) {
   DataLayoutPass *DLP = P->getAnalysisIfAvailable<DataLayoutPass>();
-  DL = DLP ? &DLP->getDataLayout() : 0;
+  DL = DLP ? &DLP->getDataLayout() : nullptr;
   TLI = P->getAnalysisIfAvailable<TargetLibraryInfo>();
   AA = &P->getAnalysis<AliasAnalysis>();
 }