Add FixItHint for -Wnull-conversion to initialize with an appropriate literal.

Reviewed by Doug Gregor.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@155839 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index d12f707..a9557a5 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -4220,7 +4220,8 @@
     if (Loc.isMacroID())
       Loc = S.SourceMgr.getImmediateExpansionRange(Loc).first;
     S.Diag(Loc, diag::warn_impcast_null_pointer_to_integer)
-        << T << Loc << clang::SourceRange(CC);
+        << T << clang::SourceRange(CC)
+        << FixItHint::CreateReplacement(Loc, S.getFixItZeroLiteralForType(T));
     return;
   }