glib: Add 2.50 availibity macros

https://bugzilla.gnome.org/show_bug.cgi?id=665446

docs/reference/glib/glib-sections.txt

@@ -128,6 +128,7 @@ GLIB_VERSION_2_42
 GLIB_VERSION_2_44
 GLIB_VERSION_2_46
 GLIB_VERSION_2_48
+GLIB_VERSION_2_50
 GLIB_VERSION_MIN_REQUIRED
 GLIB_VERSION_MAX_ALLOWED
 GLIB_DISABLE_DEPRECATION_WARNINGS
@@ -147,6 +148,7 @@ GLIB_AVAILABLE_IN_2_42
 GLIB_AVAILABLE_IN_2_44
 GLIB_AVAILABLE_IN_2_46
 GLIB_AVAILABLE_IN_2_48
+GLIB_AVAILABLE_IN_2_50
 GLIB_DEPRECATED_IN_2_26
 GLIB_DEPRECATED_IN_2_26_FOR
 GLIB_DEPRECATED_IN_2_28
@@ -171,6 +173,8 @@ GLIB_DEPRECATED_IN_2_46
 GLIB_DEPRECATED_IN_2_46_FOR
 GLIB_DEPRECATED_IN_2_48
 GLIB_DEPRECATED_IN_2_48_FOR
+GLIB_DEPRECATED_IN_2_50
+GLIB_DEPRECATED_IN_2_50_FOR
 GLIB_VERSION_CUR_STABLE
 GLIB_VERSION_PREV_STABLE
 </SECTION>

glib/gversionmacros.h

@@ -155,6 +155,16 @@
  */
 #define GLIB_VERSION_2_48       (G_ENCODE_VERSION (2, 48))
 
+/**
+ * GLIB_VERSION_2_50:
+ *
+ * A macro that evaluates to the 2.50 version of GLib, in a format
+ * that can be used by the C pre-processor.
+ *
+ * Since: 2.50
+ */
+#define GLIB_VERSION_2_50       (G_ENCODE_VERSION (2, 50))
+
 /* evaluates to the current stable version; for development cycles,
  * this means the next stable target
  */
@@ -414,5 +424,18 @@
 # define GLIB_AVAILABLE_IN_2_48                 _GLIB_EXTERN
 #endif
 
+#if GLIB_VERSION_MIN_REQUIRED >= GLIB_VERSION_2_50
+# define GLIB_DEPRECATED_IN_2_50                GLIB_DEPRECATED
+# define GLIB_DEPRECATED_IN_2_50_FOR(f)         GLIB_DEPRECATED_FOR(f)
+#else
+# define GLIB_DEPRECATED_IN_2_50                _GLIB_EXTERN
+# define GLIB_DEPRECATED_IN_2_50_FOR(f)         _GLIB_EXTERN
+#endif
+
+#if GLIB_VERSION_MAX_ALLOWED < GLIB_VERSION_2_50
+# define GLIB_AVAILABLE_IN_2_50                 GLIB_UNAVAILABLE(2, 50)
+#else
+# define GLIB_AVAILABLE_IN_2_50                 _GLIB_EXTERN
+#endif
 
 #endif /*  __G_VERSION_MACROS_H__ */