[modules] Fix typo in default argument merging.

llvm-svn: 239954
diff --git a/clang/test/Modules/submodules-merge-defs.cpp b/clang/test/Modules/submodules-merge-defs.cpp
index ee5e4fe..38b3147 100644
--- a/clang/test/Modules/submodules-merge-defs.cpp
+++ b/clang/test/Modules/submodules-merge-defs.cpp
@@ -82,3 +82,4 @@
 template<typename T, int N, template<typename> class K> struct J;
 J<> post_j2;
 FriendDefArg::Y<int> friend_def_arg;
+FriendDefArg::D<> friend_def_arg_d;