Make simulator compile on MacOS

Tested on MacOS Sequoia (Apple Silicon) with the
latest Xcode command line tools, gcc 14
(Homebrew GCC 14.2.0_1) and sdl2 (Homebrew 2.30.9)

Make sure 'gcc' (and 'gcc-ar') is in your PATH
ahead of the Xcode-provided "gcc"(clang). E.g.
by setting up symlinks in /usr/local/bin that
point to gcc-14 and gcc-ar-14.

Notes:
- The appropriate bmp from uisimulator/bitmaps
  has to be manually copied to your build folder
  and renamed to UI256.bmp, if you want the sim
  background to be displayed

Change-Id: I559f33d2165065f913f30c016b85906af380fb81

apps/playback.c

@@ -3989,7 +3989,13 @@ size_t audio_get_filebuflen(void)
 
 /* How many tracks exist on the buffer - full or partial */
 unsigned int audio_track_count(void)
+#ifndef __APPLE__
     __attribute__((alias("track_list_count")));
+#else
+{
+   return track_list_count();
+}
+#endif
 
 /* Return total ringbuffer space occupied - ridx to widx */
 long audio_filebufused(void)