patch 8.1.0941: macros for MS-Windows are inconsistent
Problem: Macros for MS-Windows are inconsistent, using "32", "3264 and
others.
Solution: Use MSWIN for all MS-Windows builds. Use FEAT_GUI_MSWIN for the
GUI build. (Hirohito Higashi, closes #3932)
diff --git a/src/gui_gtk_f.c b/src/gui_gtk_f.c
index 3f376c0..d81474b 100644
--- a/src/gui_gtk_f.c
+++ b/src/gui_gtk_f.c
@@ -32,7 +32,7 @@
#if !GTK_CHECK_VERSION(3,0,0)
# include <gtk/gtksignal.h>
#endif
-#ifdef WIN3264
+#ifdef MSWIN
# include <gdk/gdkwin32.h>
#else
# include <gdk/gdkx.h>