patch 8.1.1230: a lot of code is shared between vim.exe and gvim.exe

Problem:    A lot of code is shared between vim.exe and gvim.exe.
Solution:   Optionally put the shared code in vim.dll. (Ken Takata,
            closes #4287)
diff --git a/src/ui.c b/src/ui.c
index 3f41010..972880d 100644
--- a/src/ui.c
+++ b/src/ui.c
@@ -643,7 +643,7 @@
     if (gui.in_use)
 	return gui_mch_get_winpos(x, y);
 # endif
-# if defined(MSWIN) && !defined(FEAT_GUI)
+# if defined(MSWIN) && (!defined(FEAT_GUI) || defined(VIMDLL))
     return mch_get_winpos(x, y);
 # else
 #  if defined(HAVE_TGETENT) && defined(FEAT_TERMRESPONSE)