build: Add missing "static" keyword where it should be used

Otherwise we fail to build with -Werror=missing-prototypes.

https://bugzilla.gnome.org/show_bug.cgi?id=687385

gio/gdbusactiongroup.c

@@ -92,7 +92,7 @@ action_info_free (gpointer user_data)
   g_slice_free (ActionInfo, info);
 }
 
-ActionInfo *
+static ActionInfo *
 action_info_new_from_iter (GVariantIter *iter)
 {
   const gchar *param_str;

gio/gtestdbus.c

@@ -74,7 +74,7 @@ unref_on_idle (gpointer object)
   return FALSE;
 }
 
-gboolean
+static gboolean
 _g_object_unref_and_wait_weak_notify (gpointer object)
 {
   WeakNotifyData data;

gio/tests/gdbus-peer-object-manager.c

@@ -84,7 +84,7 @@ mock_interface_get_info (GDBusInterfaceSkeleton *skeleton)
   return &interface_info;
 }
 
-GVariant *
+static GVariant *
 mock_interface_get_property (GDBusConnection *connection,
                              const gchar *sender,
                              const gchar *object_path,

gio/tests/gdbus-peer.c

@@ -1682,7 +1682,7 @@ codegen_service_thread_func (gpointer user_data)
 }
 
 
-gboolean
+static gboolean
 codegen_quit_mainloop_timeout (gpointer data)
 {
   g_main_loop_quit (loop);

gio/tests/resources.c

@@ -487,7 +487,7 @@ test_uri_query_info (void)
   g_resource_unref (resource);
 }
 
-void
+static void
 test_uri_file (void)
 {
   GResource *resource;

tests/libmoduletestplugin_a.c

@@ -30,6 +30,12 @@
 #include	<gmodule.h>
 #include	<stdlib.h>
 
+void gplugin_a_func (void);
+void gplugin_clash_func (void);
+void g_clash_func (void);
+void gplugin_say_boo_func (void);
+void gplugin_a_module_func (GModule *module);
+
 G_MODULE_EXPORT gchar* gplugin_a_state;
 
 G_MODULE_EXPORT void

tests/libmoduletestplugin_b.c

@@ -31,6 +31,14 @@
 
 G_MODULE_EXPORT gchar* gplugin_b_state;
 
+const gchar* g_module_check_init (GModule *module);
+void   g_module_unload (GModule *module);
+
+void gplugin_b_func (void);
+void gplugin_clash_func (void);
+void g_clash_func (void);
+void gplugin_say_boo_func (void);
+
 G_MODULE_EXPORT const gchar*
 g_module_check_init (GModule *module)
 {

tests/testgdate.c

@@ -29,7 +29,8 @@ else \
   if ((passed+notpassed) % 10000 == 0) g_print ("."); fflush (stdout); \
 } G_STMT_END
 
-void g_date_debug_print(GDate* d)
+static void
+g_date_debug_print (GDate* d)
 {
   if (!d) g_print("NULL!\n");
   else 

tests/testgdateparser.c

@@ -11,7 +11,8 @@
 #include <string.h>
 #include <locale.h>
 
-void g_date_debug_print(GDate* d)
+static void
+g_date_debug_print (GDate* d)
 {
   if (!d) g_print("NULL!\n");
   else 

tests/unicode-collate.c

@@ -13,7 +13,7 @@ typedef struct {
 } Line;
   
 
-int 
+static int 
 compare_collate (const void *a, const void *b)
 {
   const Line *line_a = a;
@@ -22,7 +22,7 @@ compare_collate (const void *a, const void *b)
   return g_utf8_collate (line_a->str, line_b->str);
 }
 
-int 
+static int 
 compare_key (const void *a, const void *b)
 {
   const Line *line_a = a;