Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

MFC r260880 (by kaiw, from projects/elftoolchain):

* Make die_mem_offset() be able to handle DW_AT_data_member_location
attributes generated by Clang 3.4.
* Document how different compilers generate DW_AT_data_member_location
attributes differently.
* Document the quirks about DW_FORM_data[48].

This is a slightly modified version, adapted to work with the old
libdwarf in stable/9 and stable/10. It should fix DTrace on these
branches, when the kernel is compiled with clang 3.4.

Note that you have to build *and* install the CTF tools first, before
building the kernel. Otherwise you can possibly still get error
messages similar to "failed to copy type of 'pr_uid': Type information
is in parent and unavailable", when attempting to run dtrace(1).

Submitted by: kaiw

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

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

Merge various CTF fixes from illumos

2942 CTF tools need to handle files which legitimately lack data
2978 ctfconvert still needs to ignore legitimately dataless files on SPARC

Illumos Revisions: 13745:6b3106b4250f
13754:7231b684c18b

Reference:

https://www.illumos.org/issues/2942
https://www.illumos.org/issues/2978

MFC after: 3 weeks

Fix a segfault in ctfmerge due to a bug in gcc.

GCC can generate bogus dwarf attributes with DW_AT_byte_size
set to 0xFFFFFFFF.
The issue was originaly detected in NetBSD but it has been
adapted for portability and to avoid compiler warnings.

Reference:
https://www.illumos.org/issues/3776

Obtained from: NetBSD
MFC after: 1 month

Use FreeBSD's libdwarf which is BSD licensed instead of the GPL'd one that
is used in Solaris.

This commit was generated by cvs2svn to compensate for changes in r178528,
which included commits to RCS files with non-trunk default branches.

Vendor import of the full userland contrib part of DTrace support from
OpenSolaris. This commit resets files to match the versions in the
OpenSolaris tree as of 2008/04/10.

The changes in this import from the previous import are the ones that
will subsequently re-applied to take files off the vendor branch. This
is unfortunately necessary because the Solaris developers won't allow
FreeBSD support #ifdefs in their source code because that creates
'dead code' (stuff that they never compile).

Vendor import of the CTF (Compact C Type Format) code used by DTrace
from OpenSolaris.