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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206243 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Analysis/SparsePropagation.h

@@ -82,7 +82,7 @@ public:
   /// constant value, return it.  Otherwise return null.  The returned value
   /// must be in the same LLVM type as Val.
   virtual Constant *GetConstant(LatticeVal LV, Value *Val, SparseSolver &SS) {
-    return 0;
+    return nullptr;
   }
 
   /// ComputeArgument - Given a formal argument value, compute and return a