Removing build metadata, for reproducible kernel builds

[Erik Cederstrand]

> Den 2. dec. 2015 kl. 21.03 skrev John Baldwin <jhb at freebsd.org>:
> 
> As I noted in the review, this will break kgdb -n (and possibly crashinfo,
> less certain about that).  Keeping the path (which should not vary if you
> build out of the same tree) will be sufficient to let kgdb -n still work
> (though it may need some changes to recognize both formats).

Would it be feasible to include the relative build path instead of the absolute path? I seem to remember patches floating around for the __FILE__ macro, but I don't know if (k)gdb can work with relative paths.

Erik