[glib] glib-private.h: add _glib_alignof

[Matthias Clasen <matthiasc src gnome org>]

commit 476aa9ae46098f1090fc52ab2c10859fa8bb5495
Author: Simon McVittie <simon mcvittie collabora co uk>
Date:   Fri Nov 16 12:49:15 2012 +0000

    glib-private.h: add _glib_alignof

 glib/glib-private.h |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/glib/glib-private.h b/glib/glib-private.h
index 44cbf3d..6195ad9 100644
--- a/glib/glib-private.h
+++ b/glib/glib-private.h
@@ -23,6 +23,12 @@
 #include <glib.h>
 #include "gwakeup.h"
 
+#if defined(__GNUC__)
+# define _g_alignof(type) (__alignof__ (type))
+#else
+# define _g_alignof(type) (G_STRUCT_OFFSET (struct { char a; type b; }, b))
+#endif
+
 GMainContext *          g_get_worker_context            (void);
 gboolean                g_check_setuid                  (void);
 GMainContext *          g_main_context_new_with_next_id (guint next_id);