[C++11] Use 'nullptr'. Frontend edition.

llvm-svn: 209389
diff --git a/clang/lib/Frontend/LogDiagnosticPrinter.cpp b/clang/lib/Frontend/LogDiagnosticPrinter.cpp
index 53b13fc..917c13f 100644
--- a/clang/lib/Frontend/LogDiagnosticPrinter.cpp
+++ b/clang/lib/Frontend/LogDiagnosticPrinter.cpp
@@ -19,7 +19,7 @@
 LogDiagnosticPrinter::LogDiagnosticPrinter(raw_ostream &os,
                                            DiagnosticOptions *diags,
                                            bool _OwnsOutputStream)
-  : OS(os), LangOpts(0), DiagOpts(diags),
+  : OS(os), LangOpts(nullptr), DiagOpts(diags),
     OwnsOutputStream(_OwnsOutputStream) {
 }