Simple visualization of expressions

While more could be done, showing the type is a lot better than what is there now.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@269623 91177308-0d34-0410-b5e6-96231b3b80d8

utils/ClangVisualizers/clang.natvis

@@ -415,4 +415,7 @@ For later versions of Visual Studio, no setup is required-->
       </ArrayItems>
     </Expand>
   </Type>
+  <Type Name="clang::Expr">
+    <DisplayString>Expression of type {TR,view(cpp)}</DisplayString>
+  </Type>
 </AutoVisualizer>