ENH: provide a test for today's ReadListFile() bug fix

Tests/Testing/CMakeLists.txt

@@ -67,4 +67,4 @@ ADD_TEST(testing ${Testing_BINARY_DIR}/bin/testing)
 # Force subdirs
 # (coverage)
 #
-SUBDIRS(Sub)
+SUBDIRS(Sub/Sub2)

Tests/Testing/Sub/Sub2/CMakeLists.txt

+#
+# Add test
+#
+ADD_EXECUTABLE(testing2 testing2.cxx)
+ADD_TEST(testing2 ${Testing_BINARY_DIR}/bin/testing2)

Tests/Testing/Sub/Sub2/testing2.cxx

+int main ()
+{
+  return 0;
+}