MFC r312997, r313002:
Re-import libedit 2016-02-27 and update libedit with changes from NetBSD's
2016-03-21.

Obtained from: NetBSD

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

Prune bogus svn:mergeinfo from directores on which it should not ever
be present.

Sponsored by: The FreeBSD Foundation

Revert r296175
Undo update of libedit 2016-02-27

Something in libedit appears to be causing breakage in lldb38.
The changes are not generally huge but they are suficient to
to justify reverting for now.

Reported by: novel, bapt

Upgrade our copies of clang, llvm, lldb and compiler-rt to 3.8.0
release.

Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
support to build; see UPDATING for more information.

Release notes for llvm and clang will soon be available here:
<http://llvm.org/releases/3.8.0/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.8.0/tools/clang/docs/ReleaseNotes.html>

Thanks to Ed Maste, Roman Divacky, Davide Italiano and Antoine Brodin
for their help.

Relnotes: yes

MFV r296159
Sync our libedit with NetBSD's libedit 2016-02-27.

Obtained from: NetBSD

MFV r295360
Sync our libedit with NetBSD's libedit 2016-01-16

Obtained from: NetBSD

Add META_MODE support.

Off by default, build behaves normally.
WITH_META_MODE we get auto objdir creation, the ability to
start build from anywhere in the tree.

Still need to add real targets under targets/ to build packages.

Differential Revision: D2796
Reviewed by: brooks imp

Sync with NetBSD:

- fix types of rl_completion_entry_function and rl_add_defun
- call update pos before completion to refresh the screen
From Thomas Eriksson

Adjust API to a more modern readline (Ryo Onodera)

remove duplicate declaration

Synchronize libedit with NetBSD

It incorporates and fixes our patches to get el_gets return the proper count of
characters in unicode mode.

Synchronize libedit with NetBSD and activate UTF-8 support [1]

Differences with NetBSD
Reapply our local patches on top of it
Fix Unicode environement detection
Fix reading a line in unicode environment.
It allows /bin/sh to works in UTF-8 envs

Differential Revision: https://reviews.freebsd.org/D1455
Reviewed by: jilles, pfg
Obtained from: NetBSD [1]
MFC after: 1 month
Relnotes: yes

Correct r228114 and use the same implementation for tilde.h as for history.h

Use INCSLINKS so that "make installincludes" installs links during buildworld.

- Hide _rl_qsort_string_compare() that should be private to libreadline()
implementation.
- Add symlink /usr/include/edit/readline/tilde.h -> readline.h

All this makes it possible to build and link gdb with -ledit.

Add $FreeBSD$'s.

* Add the readline(3) API to libedit. The libedit versions of
{readline,history}.h are in /usr/include/edit so as to not conflict with
the GNU libreadline versions. To use the libedit readline(3) one should
add "-I/usr/include/edit" to their Makefile
(spelled "-I${DESTDIR}/${INCLUDEDIR}/edit" within the FreeBSD source tree).

* Enable its use in the BSD licensed utilities that support readline(3).

* To make it easier to sync libedit development with NetBSD, histedit.h
is moved into libedit's directory as history shows shown we keep merging
it into that location.

Obtained from: NetBSD
Sponsored by: Juniper Networks