solved the readlinkat type conflict error on mac osx

On Mac OSX 10.10, I had the following error when ./bootstrap.sh 

    In file included from /usr/include/unistd.h:72:
    /usr/include/sys/unistd.h:206:9: error: conflicting types for 'readlinkat'
    ssize_t readlinkat(int, const char *, char *, size_t)   __OSX_AVAILABLE_...
            ^
    ../src/compat/macosx.h:36:5: note: previous declaration is here
    int readlinkat(int dirfd, const char *pathname, char *buf, size_t bufsiz);

This is solved by renaming the function readlinkat to readlinkat1.