Fixed upstream from https://github.com/vgmrips/vgmplay/pull/74
Fix for -fno-common

Index: VGMPlay/VGMPlay_AddFmts.c
--- VGMPlay/VGMPlay_AddFmts.c.orig
+++ VGMPlay/VGMPlay_AddFmts.c
@@ -117,7 +117,7 @@ extern INT32 VGMSmplPlayed;
 extern INT32 VGMSampleRate;
 extern UINT32 BlocksSent;
 extern UINT32 BlocksPlayed;
-bool VGMEnd;
+extern bool VGMEnd;
 extern bool EndPlay;
 extern bool PausePlay;
 extern bool FadePlay;
