Add 179294 back, but don't use bit fields so that it works on big endian hosts.

Original message:

Print more information about relocations.

With this patch llvm-readobj now prints if a relocation is pcrel, its length,
if it is extern and if it is scattered.

It also refactors the code a bit to use bit fields instead of shifts and
masks all over the place.

llvm-svn: 179345