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

llvm-svn: 207196
diff --git a/llvm/lib/Transforms/Utils/CmpInstAnalysis.cpp b/llvm/lib/Transforms/Utils/CmpInstAnalysis.cpp
index 8fa412a..3b15a0a 100644
--- a/llvm/lib/Transforms/Utils/CmpInstAnalysis.cpp
+++ b/llvm/lib/Transforms/Utils/CmpInstAnalysis.cpp
@@ -84,7 +84,7 @@
     case 7: // True.
       return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 1);
   }
-  return NULL;
+  return nullptr;
 }
 
 /// PredicatesFoldable - Return true if both predicates match sign or if at