error: ‘fileno’ was not declared in this scope

I am running Cygwin on windows 8, attempting to compile the source code for a game I would like to mod. Unfortunately I am running into some errors while building involving the fileno function. After doing some googling It seems like the problem might have to do with c++11 support (I'm not really sure what this means). Most of the solutions people have found involve adding some option like -std=c++0x or -std=c++11 when compiling, but my attempts to add the options into the makefile have been unsuccessful, and I don't know if that's whats causing the problem anyways. I'll include the code snippet that's throwing the error and a link to the makefile as it is quite large. Any advice you could give me would be great.

code that throws error:

    time_t file_modtime(FILE *f)
    {
        struct stat filestat;
        if (fstat(fileno(f), &filestat))
            return 0;

        return filestat.st_mtime;
    }

Link to Makefile

it is being hosted on github