gdate: Deprecate methods which use GTimeVal

GTimeVal is not year-2038-safe.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Helps: #1438

glib/gdate.c

@@ -1470,13 +1470,17 @@ G_GNUC_END_IGNORE_DEPRECATIONS
  * The time to date conversion is done using the user's current timezone.
  *
  * Since: 2.10
+ * Deprecated: 2.62: #GTimeVal is not year-2038-safe. Use g_date_set_time_t()
+ *    instead.
  */
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
 void
 g_date_set_time_val (GDate    *date,
 		     GTimeVal *timeval)
 {
   g_date_set_time_t (date, (time_t) timeval->tv_sec);
 }
+G_GNUC_END_IGNORE_DEPRECATIONS
 
 /**
  * g_date_set_month:

glib/gdate.h

@@ -195,10 +195,10 @@ void         g_date_set_parse             (GDate       *date,
 GLIB_AVAILABLE_IN_ALL
 void         g_date_set_time_t            (GDate       *date,
 					   time_t       timet);
-GLIB_AVAILABLE_IN_ALL
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+GLIB_DEPRECATED_IN_2_62_FOR(g_date_set_time_t)
 void         g_date_set_time_val          (GDate       *date,
 					   GTimeVal    *timeval);
-G_GNUC_BEGIN_IGNORE_DEPRECATIONS
 GLIB_DEPRECATED_FOR(g_date_set_time_t)
 void         g_date_set_time              (GDate       *date,
                                            GTime        time_);