[gtk/master.msvc] demos: Fix builds against Visual Studio headers

[Chun-wei Fan <fanchunwei src gnome org>]

commit 293f2e6b1c1a01efcd040f54711e614c0850bfa1
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Mon Jun 22 17:04:18 2020 +0800

    demos: Fix builds against Visual Studio headers
    
    According to [1], '_timezone' is already used for a global variable in the
    time.h system header that is supplied by Microsoft, so using that for our
    variable name when we are including time.h either directly or indirectly
    will cause trouble.
    
    This renames such variables to '_tz' to avoid that
    
    [1]: https://docs.microsoft.com/en-us/cpp/c-runtime-library/daylight-dstbias-timezone-and-tzname

 demos/gtk-demo/listview_clocks.c  | 6 +++---
 demos/gtk-demo/listview_weather.c | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)
---
diff --git a/demos/gtk-demo/listview_clocks.c b/demos/gtk-demo/listview_clocks.c
index 28bff1e645..6ba1ec5377 100644
--- a/demos/gtk-demo/listview_clocks.c
+++ b/demos/gtk-demo/listview_clocks.c
@@ -323,16 +323,16 @@ gtk_clock_init (GtkClock *self)
 
 static GtkClock *
 gtk_clock_new (const char *location,
-               GTimeZone  *_timezone)
+               GTimeZone  *_tz)
 {
   GtkClock *result;
 
   result = g_object_new (GTK_TYPE_CLOCK,
                          "location", location,
-                         "timezone", _timezone,
+                         "timezone", _tz,
                          NULL);
 
-  g_clear_pointer (&_timezone, g_time_zone_unref);
+  g_clear_pointer (&_tz, g_time_zone_unref);
 
   return result;
 }
diff --git a/demos/gtk-demo/listview_weather.c b/demos/gtk-demo/listview_weather.c
index 4fa83721f4..e87304d1aa 100644
--- a/demos/gtk-demo/listview_weather.c
+++ b/demos/gtk-demo/listview_weather.c
@@ -77,13 +77,13 @@ gtk_weather_info_new (GDateTime      *timestamp,
 
 static GDateTime *
 parse_timestamp (const char *string,
-                 GTimeZone  *_timezone)
+                 GTimeZone  *_tz)
 {
   char *with_seconds;
   GDateTime *result;
 
   with_seconds = g_strconcat (string, ":00", NULL);
-  result = g_date_time_new_from_iso8601 (with_seconds, _timezone);
+  result = g_date_time_new_from_iso8601 (with_seconds, _tz);
   g_free (with_seconds);
 
   return result;