Adds x86 NONE relocation type

Summary:
As reported by Alex Lang, R_X86_64_NONE relocations
appear in per-package object files, not per-module object
files. This diff adds _NONE relocations for x86.

Reviewers: bgamari, geekosaur, austin, erikd, simonmar

Reviewed By: geekosaur

Subscribers: rwbarton, thomie

Differential Revision: https://phabricator.haskell.org/D4062