Removed GTK2/GTK3 dual-path preprocessor branches across src/fe-gtk by keeping GTK3-native paths only, including the high-density targets you prioritized (xtext.c, setup.c, maingui.c, gtkutil.c, servlistgui.c).

Removed GTK2 compatibility shims from headers (fe-gtk.h, gtkutil.h), leaving direct GTK3-facing declarations/includes only (and platform-specific guards unrelated to GTK2 kept as-is).

Cleaned GTK2-specific comments/wording now that behavior is GTK3-native (menu accelerator note and emoji/userlist comment blocks).

src/fe-gtk/custom-list.h

@@ -73,11 +73,7 @@ chanlistrow;
  *             structure.                                          */
 struct _CustomList
 {
-#if HAVE_GTK3
 	GObject parent_instance;
-#else
-	GObject parent;
-#endif
 
 	guint num_rows;     /* number of rows that we have used */
 	guint num_alloc;    /* number of rows allocated */