[C++11] Use 'nullptr'.

llvm-svn: 210442
diff --git a/llvm/unittests/ADT/APFloatTest.cpp b/llvm/unittests/ADT/APFloatTest.cpp
index 86a48bf..8f298cd 100644
--- a/llvm/unittests/ADT/APFloatTest.cpp
+++ b/llvm/unittests/ADT/APFloatTest.cpp
@@ -1173,11 +1173,11 @@
   EXPECT_TRUE(inv.bitwiseIsEqual(APFloat(8.5070592e+37f)));
 
   // Large float, inverse is a denormal.
-  EXPECT_FALSE(APFloat(1.7014118e38f).getExactInverse(0));
+  EXPECT_FALSE(APFloat(1.7014118e38f).getExactInverse(nullptr));
   // Zero
-  EXPECT_FALSE(APFloat(0.0).getExactInverse(0));
+  EXPECT_FALSE(APFloat(0.0).getExactInverse(nullptr));
   // Denormalized float
-  EXPECT_FALSE(APFloat(1.40129846e-45f).getExactInverse(0));
+  EXPECT_FALSE(APFloat(1.40129846e-45f).getExactInverse(nullptr));
 }
 
 TEST(APFloatTest, roundToIntegral) {