Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Repair some build breakage introduced in r211725 and garbage collect some
code made obsolete in the same commit.

MFtbemd:

Prefer MACHNE_CPUARCH to MACHINE_ARCH in most contexts where you want
to test of all the CPUs of a given family conform.

These are the things that the tinderbox has problems with because it
doesn't use the default CFLAGS which contain -fno-strict-aliasing.

Until the code is cleaned up, just add -fno-strict-aliasing to the
CFLAGS of these for the tinderboxes' sake, allowing the rest of the
tree to have -Werror enabled again.

Build shared on PowerPC now that the bug has been found and fixed.

Use NO_SHARED=YES to force a static link.

Pointed out by: ru@

Link kldxref(8) static on PowerPC to work around a SIGSEGV that
cannot easily be analyzed due to there being no debugger yet.
The SIGSEGV only happens when kldxref is linked shared.
Since kldxref(8) is needed for a release build, having it not
dump core is important.

Add support for reading ELF relocatable object file format modules.

style.Makefile(5)

Fix kldxref on sparc64 by allowing non-trivial relocations to be performed
on variables read out of raw kld files. Unlike other platforms the value
will be in an Elf_Rela, not in the data section of the elf file.

Submitted by: Hartmut Brandt <brandt@fokus.gmd.de>
PR: 46730
Tested on: alpha (obrien), i386, sparc64

Reorder WARNS line for style.

Pointed out by: bde

WARNS=2 cleanup.

PR: bin/32567
MFC after: 2 weeks

Write a real man page.

Add kldxref(8), for maintaining the linker.hints file for translating
module->pathname.ko. It supports only ELF for now.

Submitted by: bp (with some minor tweaks)