Remove mg_stat

src/fs.h

@@ -2,9 +2,4 @@
 
 #include "arch.h"
 
-#ifdef _WIN32
-typedef struct _stati64 mg_stat_t;
-#else
-typedef struct stat mg_stat_t;
-#endif
-int mg_stat(const char *path, mg_stat_t *);
+FILE *fopen_packed(const char *path, const char *mode);