objtool: sync up with the 4.14.47 version of objtool

There are pros and cons of dealing with tools in the kernel directory.
The pros are the fact that development happens fast, and new features
can be added to the kernel and the tools at the same times.  The cons
are when dealing with backported kernel patches, it can be necessary to
backport parts of the tool changes as well.

For 4.9.y so far, we have backported individual patches.  That quickly
breaks down when there are minor differences between how backports were
handled, so grabbing 40+ patch long series can be difficult, not
impossible, but really frustrating to attempt.

To help mitigate this mess, here's a single big patch to sync up the
objtool logic to the 4.14.47 version of the tool.  From this point
forward (after some other minor header file patches are applied), the
tool should be in sync and much easier to maintain over time.

This has survivied my limited testing, and as the codebase is identical
to 4.14.47, I'm pretty comfortable dropping this big change in here in
4.9.y.  Hopefully all goes well...

Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>