Cross platform path exists test

path_exists.c

/* returns true if the dir or file exists */
FTGDEF bool
ftg_path_exists(const char *path)
{
#ifdef FTG_POSIX_LIKE
    return access(path, F_OK) != -1;
#elif defined(_WIN32)
    ftg_wchar_t u8_path[MAX_PATH];
    DWORD attrib;
    
    ftg_wchar_from_u8(path, u8_path, MAX_PATH);
    attrib = GetFileAttributesW(u8_path);
        
    return (attrib != INVALID_FILE_ATTRIBUTES);
#endif    
}