DIBuilder: Correct the null/0 type of trailing fields in struct debug info.

Paired with an Clang commit so this may cause temporary build failures.

llvm-svn: 175426
diff --git a/llvm/lib/IR/DIBuilder.cpp b/llvm/lib/IR/DIBuilder.cpp
index 2fe13c4..16632a1 100644
--- a/llvm/lib/IR/DIBuilder.cpp
+++ b/llvm/lib/IR/DIBuilder.cpp
@@ -526,8 +526,8 @@
     NULL,
     Elements,
     ConstantInt::get(Type::getInt32Ty(VMContext), RunTimeLang),
-    ConstantInt::get(Type::getInt32Ty(VMContext), 0),
-    ConstantInt::get(Type::getInt32Ty(VMContext), 0),
+    NULL,
+    NULL,
   };
   return DIType(MDNode::get(VMContext, Elts));
 }