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

llvm-svn: 209070
diff --git a/clang/lib/ASTMatchers/Dynamic/VariantValue.cpp b/clang/lib/ASTMatchers/Dynamic/VariantValue.cpp
index 9c7262e..18c98943 100644
--- a/clang/lib/ASTMatchers/Dynamic/VariantValue.cpp
+++ b/clang/lib/ASTMatchers/Dynamic/VariantValue.cpp
@@ -71,7 +71,7 @@
 
   virtual void makeTypedMatcher(MatcherOps &Ops) const {
     bool FoundIsExact = false;
-    const DynTypedMatcher *Found = NULL;
+    const DynTypedMatcher *Found = nullptr;
     int NumFound = 0;
     for (size_t i = 0, e = Matchers.size(); i != e; ++i) {
       bool IsExactMatch;