Please backport r323625 and dependencies to 6.0

[llvmbot]

Bugzilla Link	36136
Resolution	FIXED
Resolved on	Jan 30, 2018 01:20
Version	unspecified
OS	Linux
Blocks	#35152
Reporter	LLVM Bugzilla Contributor
CC	@DimitryAndric,@emaste,@zmodem,@rui314

Extended Description

It depends on

r323396
r323399
r323440
r323449
r323456

Backporting r323625 should allow lld 6.0 to build a freebsd kernel that works with Xen.

If this is too much to backport, I can try to write a more target backport.

[emaste]

For reference I've backported these (and also r323395) into lld 6 in FreeBSD as r328542 through r328548 inclusive. https://svnweb.freebsd.org/changeset/base/328548

I started looking at trying to adapt r323625 to apply directly, but on inspection the dependencies were small and self-contained enough that it made sense to just import the whole series.

[zmodem]

I've merged them all in r323733.