Allow for user song list (#9281)

.gitignore

@@ -73,3 +73,6 @@ __pycache__
 
 # prerequisites for updating ChibiOS
 /util/fmpp*
+
+# Allow to exist but don't include it in the repo
+user_song_list.h

quantum/audio/song_list.h

@@ -20,6 +20,12 @@
 
 #include "musical_notes.h"
 
+#if __GNUC__ > 5  // don't use for older gcc compilers since check isn't supported.
+#    if __has_include("user_song_list.h")
+#        include "user_song_list.h"
+#    endif  // if file exists
+#endif      // __GNUC__
+
 #define NO_SOUND
 
 /* Ode to Joy
@@ -146,44 +152,126 @@
  *   proof of permission to use them, or public domain status.
  */
 
+#ifndef CLOSE_ENCOUNTERS_5_NOTE
 #    define CLOSE_ENCOUNTERS_5_NOTE
+#endif
+#ifndef DOE_A_DEER
 #    define DOE_A_DEER
+#endif
+#ifndef IN_LIKE_FLINT
 #    define IN_LIKE_FLINT
+#endif
+#ifndef IMPERIAL_MARCH
 #    define IMPERIAL_MARCH
+#endif
+#ifndef BASKET_CASE
 #    define BASKET_CASE
+#endif
+#ifndef COIN_SOUND
 #    define COIN_SOUND
+#endif
+#ifndef ONE_UP_SOUND
 #    define ONE_UP_SOUND
+#endif
+#ifndef SONIC_RING
 #    define SONIC_RING
+#endif
+#ifndef ZELDA_PUZZLE
 #    define ZELDA_PUZZLE
+#endif
+#ifndef ZELDA_TREASURE
 #    define ZELDA_TREASURE
+#endif
+#ifndef OVERWATCH_THEME
 #    define OVERWATCH_THEME
+#endif
+#ifndef MARIO_THEME
 #    define MARIO_THEME
+#endif
+#ifndef MARIO_GAMEOVER
 #    define MARIO_GAMEOVER
+#endif
+#ifndef MARIO_MUSHROOM
 #    define MARIO_MUSHROOM
+#endif
+#ifndef E1M1_DOOM
 #    define E1M1_DOOM
+#endif
+#ifndef DISNEY_SONG
 #    define DISNEY_SONG
+#endif
+#ifndef NUMBER_ONE
 #    define NUMBER_ONE
+#endif
+#ifndef CABBAGE_SONG
 #    define CABBAGE_SONG
+#endif
+#ifndef OLD_SPICE
 #    define OLD_SPICE
+#endif
+#ifndef VICTORY_FANFARE_SHORT
 #    define VICTORY_FANFARE_SHORT
+#endif
+#ifndef ALL_STAR
 #    define ALL_STAR
+#endif
+#ifndef RICK_ROLL
 #    define RICK_ROLL
+#endif
+#ifndef FF_PRELUDE
 #    define FF_PRELUDE
+#endif
+#ifndef TO_BOLDLY_GO
 #    define TO_BOLDLY_GO
+#endif
+#ifndef KATAWARE_DOKI
 #    define KATAWARE_DOKI
+#endif
+#ifndef MEGALOVANIA
 #    define MEGALOVANIA
+#endif
+#ifndef MICHISHIRUBE
 #    define MICHISHIRUBE
+#endif
+#ifndef LIEBESLEID
 #    define LIEBESLEID
+#endif
+#ifndef MELODIES_OF_LIFE
 #    define MELODIES_OF_LIFE
+#endif
+#ifndef EYES_ON_ME
 #    define EYES_ON_ME
+#endif
+#ifndef SONG_OF_THE_ANCIENTS
 #    define SONG_OF_THE_ANCIENTS
+#endif
+#ifndef NIER_AMUSEMENT_PARK
 #    define NIER_AMUSEMENT_PARK
+#endif
+#ifndef COPIED_CITY
 #    define COPIED_CITY
+#endif
+#ifndef VAGUE_HOPE_COLD_RAIN
 #    define VAGUE_HOPE_COLD_RAIN
+#endif
+#ifndef KAINE_SALVATION
 #    define KAINE_SALVATION
+#endif
+#ifndef WEIGHT_OF_THE_WORLD
 #    define WEIGHT_OF_THE_WORLD
+#endif
+#ifndef ISABELLAS_LULLABY
 #    define ISABELLAS_LULLABY
+#endif
+#ifndef TERRAS_THEME
 #    define TERRAS_THEME
+#endif
+#ifndef RENAI_CIRCULATION
 #    define RENAI_CIRCULATION
+#endif
+#ifndef PLATINUM_DISCO
 #    define PLATINUM_DISCO
+#endif
+#ifndef LP_NUMB
 #    define LP_NUMB
+#endif