MFC r304055:
Fix handling of forward enum declarations in the CTF tools.

MFC r277300 (by smh): Mechanically convert cddl sun #ifdef's to illumos

Since the upstream for cddl code is now illumos not sun, mechanically
convert all sun #ifdef's to illumos #ifdef's which have been used in all
newer code for some time.

Also do a manual pass to correct the use if #ifdef comments as per style(9)
as well as few uses of #if defined(__FreeBSD__) vs #ifndef illumos.

MFC r289866:
DWARF emitted by clang 3.7 encodes array sizes using the DW_AT_count
attribute rather than DW_AT_upper_bound. Teach ctfconvert about this so that
array type sizes are encoded correctly.

PR: 203772

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

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