Added SDL_VARIABLE_LENGTH_ARRAY so this #ifdef is localized to one place.

src/audio/SDL_sysaudio.h

@@ -105,11 +105,7 @@ typedef struct SDL_AudioDeviceItem
 {
     void *handle;
     struct SDL_AudioDeviceItem *next;
-    #if (defined(__GNUC__) && (__GNUC__ <= 2))
-    char name[1];  /* actually variable length. */
-    #else
-    char name[];
-    #endif
+    char name[SDL_VARIABLE_LENGTH_ARRAY];
 } SDL_AudioDeviceItem;