[modules] Additional tests.

llvm-svn: 293223
diff --git a/clang/test/Modules/Inputs/hidden-names/visible.h b/clang/test/Modules/Inputs/hidden-names/visible.h
new file mode 100644
index 0000000..3dfc9c7
--- /dev/null
+++ b/clang/test/Modules/Inputs/hidden-names/visible.h
@@ -0,0 +1,2 @@
+// hidden-names/visible.h
+namespace NS {}