Latest clang git has a warning -Wnull-pointer-arithmetic which will
trigger a -Werror failure. Addition and subtraction from a null pointer
is undefined behaviour and could be optimized into anything.

Furthermore, using the difference between two pointers and casting the
result back to a pointer is not portable since the size of ptrdiff_t
does not necessary have to be the same as size of void* (this happens
e.g. on CHERI). Using intptr_t instead fixes this portability issue and
the compiler warning.

Submitted by;	Alexander Richardson
Obtained from:	CheriBSD
Differential Revision: https://reviews.freebsd.org/D12928
MFC after:	3 days

libiberty currently defines the prototype for basename() itself instead
of using <libgen.h>. It still uses the BSD-style prototype instead of
the POSIX one, meaning that if FreeBSD would switch over to the POSIX
one, you wouldn't be able to use libiberty.h and libgen.h in a single
source file. It turns out that kgdb does this. Patch up libiberty to
just include <libgen.h>.

I'm currently talking to upstream to see whether we can come up with a
more complete solution that could be integrated, but for our
unmaintained copy of GDB in base, let's just apply the simplest
workaround possible.

Reviewed by:	pfg
Differential Revision:	https://reviews.freebsd.org/D6631

to include the Unaligned Access and Floating-point Half-precision
attributes. the former marks ELF objects that may access ARMv6 style
unaligned data, the latter that the binary uses the VFPv3/Advanced SIMD
half-precision extension.

These may be emmitted by clang so it's best to print a warning when the
linker hits one of them.

Differential Revision:	http://reviews.freebsd.org/D2194
Submitted by:	Michal Meloun <meloun@miracle.cz>
MFC after:	1 week

Summary:
LLVM/Clang generates relocations that our binutils doesn't understand, but newer
binutils does.  I got permission from the author of a series of patches to
relicense them as GPLv2 for use in FreeBSD.  The upstream git hashes are:

ac2df442ac7901f00af15b272fc48b594b433713
2b95367962dc14f69d3c338c4d54195266e2e169
102890f04c44b64cf5cef4588267dd9f24086ac7
b7fcf6f6bb53b5027e111107f5416769cb9a5798
1d483afedd5a628dc84fb58d1d570f79fdfbfa7b
90aecf7a80c1cefeb45fc10a6cd02c8338e34b4c
3a71aa26df2a372a58e9c11ef9ba51fd0e83320a
727fc41e077139570ea8b8ddfd6c546b2a55627c

With the import of clang 3.5, and a few backported patches, we should be able to
move powerpc and powerpc64 to clang-as-cc soon.

Test Plan: Passes make tinderbox, so no regressions.  Binaries built with clang
run on powerpc64.

Reviewers: #committers, dim

Reviewed By: dim

Differential Revision: https://reviews.freebsd.org/D1297

Obtained from:	Alan Modra, upstream binutils-gdb git
MFC after:	3 weeks
Relnotes:	yes

- Dump an NT_X86_XSTATE note if XSAVE is in use. This note is designed
  to match what Linux does in that 1) it dumps the entire XSAVE area
  including the fxsave state, and 2) it stashes a copy of the current
  xsave mask in the unused padding between the fxsave state and the
  xstate header at the same location used by Linux.
- Teach readelf() to recognize NT_X86_XSTATE notes.
- Change PT_GET/SETXSTATE to take the entire XSAVE state instead of
  only the extra portion. This avoids having to always make two
  ptrace() calls to get or set the full XSAVE state.
- Add a PT_GET_XSTATE_INFO which returns the length of the current
  XSTATE save area (so the size of the buffer needed for PT_GETXSTATE)
  and the current XSAVE mask (%xcr0).

Differential Revision:	https://reviews.freebsd.org/D1193
Reviewed by:	kib
MFC after:	2 weeks

handle merging this tag correctly, however it's unused.

for. This is useful for software needing to know which architecture a
binary is built for as arm and armv6 have slight differences meaning only
some binaries build for one will work as expected on the other. It is
expected pkgng will be able to make use of this to simplify the logic to
determine which package ABI to use.

Approved by:	re (kib)

Add four ELF note constants:
- NT_FILE and NT_SIGINFO (core file notes output by recent Linux kernels)
- NT_GNU_ABI_TAG (was incorrectly reported as NT_VERSION)
- NT_GNU_BUILD_ID (used for locating standalone debug files)

Approved by:	re (kib)

Add a function to return the specific type, when the note's Name field is
'FreeBSD'.

r249558 added FreeBSD-specific ELF note types that reuse type numbers of
existing generic / Linux types.  This caused 'readelf -n' to produce
incorrect output on FreeBSD core files.

Sponsored by:	DARPA, AFRL
MFC after:	3 days