[gtk] Add GTK_CSS_PARSER_WARNING_UNIMPLEMENTED

[Matthias Clasen <matthiasc src gnome org>]

commit 9389768a176e6ee6fb43dddb5064ebbfd68b253d
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Jun 22 01:12:27 2019 -0400

    Add GTK_CSS_PARSER_WARNING_UNIMPLEMENTED
    
    gtk-doc was complaining about it missing,
    and it is used in some ifdefed code.

 gtk/css/gtkcssenums.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/gtk/css/gtkcssenums.h b/gtk/css/gtkcssenums.h
index 5470a61e51..8674696b3a 100644
--- a/gtk/css/gtkcssenums.h
+++ b/gtk/css/gtkcssenums.h
@@ -73,7 +73,8 @@ typedef enum
 typedef enum
 {
   GTK_CSS_PARSER_WARNING_DEPRECATED,
-  GTK_CSS_PARSER_WARNING_SYNTAX
+  GTK_CSS_PARSER_WARNING_SYNTAX,
+  GTK_CSS_PARSER_WARNING_UNIMPLEMENTED
 } GtkCssParserWarning;
 
 #endif /* __GTK_CSS_ENUMS_H__ */