When dumping the AST to JSON, dump the argument name to a sizeof pack expression.

llvm-svn: 361766
diff --git a/clang/test/AST/ast-dump-expr-json.cpp b/clang/test/AST/ast-dump-expr-json.cpp
index 81c3e66..0c54166 100644
--- a/clang/test/AST/ast-dump-expr-json.cpp
+++ b/clang/test/AST/ast-dump-expr-json.cpp
@@ -1505,7 +1505,8 @@
 // CHECK-NEXT:        "type": {
 // CHECK-NEXT:         "qualType": "unsigned long"
 // CHECK-NEXT:        },
-// CHECK-NEXT:        "valueCategory": "rvalue"
+// CHECK-NEXT:        "valueCategory": "rvalue",
+// CHECK-NEXT:        "name": "Ts"
 // CHECK-NEXT:       },
 // CHECK-NEXT:       {
 // CHECK-NEXT:        "id": "0x{{.*}}",