clang-format: [js] Do not fall through for JS structural elements.

Patch by Martin Probst. Thank you.

llvm-svn: 229862
diff --git a/clang/unittests/Format/FormatTestJS.cpp b/clang/unittests/Format/FormatTestJS.cpp
index 8c74b04..b60e470 100644
--- a/clang/unittests/Format/FormatTestJS.cpp
+++ b/clang/unittests/Format/FormatTestJS.cpp
@@ -521,6 +521,8 @@
                "    return 'y';\n"
                "  }\n"
                "}");
+  verifyFormat("class X {}\n"
+               "class Y {}");
 }
 
 } // end namespace tooling