Add elfutils 0.163

Elfutils is a collection of utilities, including: stack (to show
backtraces); nm (for listing symbols from object files); size (for
listing the section sizes of an object or archive file); strip (for
discarding symbols); readelf (to see the raw ELF file structures);
elflint (to check for well-formed ELF files); and elfcompress (to
compress or decompress ELF sections).

It also provides libraries to allow other programs to manipulate ELF and
DWARF data.

WWW: https://fedorahosted.org/elfutils/

Reviewed by: bdrewery
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D7206