patch 8.0.1123: cannot define a toolbar for a window

Problem:    Cannot define a toolbar for a window.
Solution:   Add a window-local toolbar.
diff --git a/src/Makefile b/src/Makefile
index 247fee6..ad96784 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -2278,6 +2278,7 @@
 	test_vimscript \
 	test_virtualedit \
 	test_visual \
+	test_winbar \
 	test_window_cmd \
 	test_window_id \
 	test_windows_home \