Apparently the deprecation warning macros are placed into gdkconfig.h
during the configure stage, so put these in the pre-configured
gdkconfig.h.win32 as well, as their definitions are needed for all builds.
G_BEGIN_DECLS
+/* These macros are used to mark deprecated functions in GDK and
+ * GTK+ headers, and thus have to be exposed in installed headers.
+ * But please do *not* use them in other projects. Instead, use
+ * G_DEPRECATED or define your own wrappers around it.
+ */
+
+#ifdef GDK_DISABLE_DEPRECATION_WARNINGS
+#define GDK_DEPRECATED
+#define GDK_DEPRECATED_FOR(f)
+#else
+#define GDK_DEPRECATED G_DEPRECATED
+#define GDK_DEPRECATED_FOR(f) G_DEPRECATED_FOR(f)
+#endif
#define GDK_WINDOWING_WIN32