sys: add a few extra preprocessor bits to fix abi tests

Author: jf2048

gio/sys/tests/manual.h

@@ -11,3 +11,5 @@
 #include <gio/gunixmounts.h>
 #include <gio/gunixoutputstream.h>
 #include <gio/gunixsocketaddress.h>
+#define G_SETTINGS_ENABLE_BACKEND 1
+#include <gio/gsettingsbackend.h>

glib/sys/tests/manual.h

@@ -2,3 +2,8 @@
 
 #include <glib.h>
 #include <glib-object.h>
+
+// included in Gir on all platforms even though it is only present on windows
+#ifndef G_WIN32_MSG_HANDLE
+#define G_WIN32_MSG_HANDLE 19981206
+#endif