Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Document why we use -z nonexecstack in the Makefile since it
is so unusual. Turn off mis-match warnings for building uathload
because the firmware .o file is produced in a way that we
can't get to match exactly. This fixes the build on mips,
so stop excluding it from the build.

Fix not skipping uathload for mips after r291021.

Sponsored by: EMC / Isilon Storage Division

Build ofwdump(8) on MIPS too

It will be useful as FDT sees increasing usage on FreeBSD/mips.

Sponsored by: DARPA, AFRL

Assume a big-endian default on MIPS and drop the "eb" suffix from MACHINE_ARCH.
This makes our naming scheme more closely match other systems and the
expectations of much third-party software. MIPS builds which are little-endian
should require and exhibit no changes. Big-endian TARGET_ARCHes must be
changed:
From: To:
mipseb mips
mipsn32eb mipsn32
mips64eb mips64

An entry has been added to UPDATING and some foot-shooting protection (complete
with warnings which should become errors in the near future) to the top-level
base system Makefile.

sysinstall was removed from usr.sbin/Makefile in r225937. Because per-arch
Makefiles were split out in this directory and others in userland, it makes it
quite easy to miss per-arch conditionals when changing something generally.

Fix n32 compile.

These changes are needed to fix n32 compile after the recent change of
mips n32 MACHINE_ARCH to mipsn32eb/mipsn32el.

Reviewed by: imp, bz (earlier version)

Retire TARGET_ABI.

Implement MACHINE_ARCH=mips64e[lb] to build N64 images. This replaces
MACHINE_ARCH=mipse[lb] TARGET_ABI=n64.

MACHINE_ARCH=mipsn32e[lb] has been added, but currently requires
WITHOUT_CDDL due to atomic issues in libzfs. I've not investigated
this much, but implemented this to preserve as much of the TARGET_ABI
functionality that I could. Since its presence doesn't affect the
working cases, I've kept it in for now.

Added mips64e[lb] to make universe, so more kernels build.

And I think this (finally) closes the curtain on the tbemd tree.

Merge from tbemd: use Makefile.arch to control building.

Reviewed by: arch@ (many times, no objection)