Export glib_init via GLIB_PRIVATE_CALL

This will be used in the next commit to call glib_init from the
gobject constructor, to ensure proper constructor ordering with
non-GNU libc.

https://bugzilla.gnome.org/show_bug.cgi?id=756139

glib/glib-init.c

@@ -228,7 +228,7 @@ g_debug_init (void)
   g_mem_gc_friendly = flags & 1;
 }
 
-static void
+void
 glib_init (void)
 {
   static gboolean glib_inited;

glib/glib-init.h

@@ -25,6 +25,7 @@
 extern GLogLevelFlags g_log_always_fatal;
 extern GLogLevelFlags g_log_msg_prefix;
 
+void glib_init (void);
 void g_quark_init (void);
 
 #ifdef G_OS_WIN32

glib/glib-private.c

@@ -20,6 +20,7 @@
 #include "config.h"
 
 #include "glib-private.h"
+#include "glib-init.h"
 
 /**
  * glib__private__:
@@ -32,6 +33,8 @@ GLibPrivateVTable *
 glib__private__ (void)
 {
   static GLibPrivateVTable table = {
+    glib_init,
+
     g_wakeup_new,
     g_wakeup_free,
     g_wakeup_get_pollfd,

glib/glib-private.h

@@ -61,6 +61,9 @@ typedef struct {
                                                          guint        flags);
   GDir *                (* g_dir_new_from_dirp)         (gpointer dirp);
 
+  /* See glib-init.c */
+  void                  (* glib_init)                   (void);
+
   /* Add other private functions here, initialize them in glib-private.c */
 } GLibPrivateVTable;