patch 8.1.1904: cannot have an info popup align with the popup menu

Problem:    Cannot have an info popup align with the popup menu.
Solution:   Add the "align" item to 'completepopup'.
diff --git a/src/vim.h b/src/vim.h
index 4a86177..6d89f03 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -623,6 +623,7 @@
 #define POPF_RESIZE	0x40	// popup can be resized by dragging
 #define POPF_MAPPING	0x80	// mapping keys
 #define POPF_INFO	0x100	// used for info of popup menu
+#define POPF_INFO_MENU	0x200	// align info popup with popup menu
 
 #ifdef FEAT_TEXT_PROP
 # define WIN_IS_POPUP(wp) ((wp)->w_popup_flags != 0)