Synchronize libcxxrt in stable/10 with stable/11.

MFC r284553 (by emaste):

Update libcxxrt upgrade instructions

The typeinfo file no longer exists upstream.

MFC r297299:

Compile libcxxrt as C++11, since it is only really used in combination
with libc++, which is also C++11. Also change one _Static_assert (which
is really C11) back into static_assert, like upstream.

This should help when compiling libcxxrt with newer versions of gcc,
which refuse to recognize any form of static assertions, if not
compiling for C++11 or higher.

While here, add -nostdinc++ to CFLAGS, to prevent picking up any C++
headers outside the source tree.

MFC r299144:

Import libcxxrt master 516a65c109eb0a01e5e95fbef455eb3215135cef.

Interesting fixes:
3adaa2e Fix _Unwind_Exception cleanup functions
286776c Check exception cleanup function ptr before calling
edda626 Correct exception specifications on new and delete operators

MFC r303157 (by emaste):

libcxxrt: add padding in __cxa_allocate_* to fix alignment

The addition of the referenceCount to __cxa_allocate_exception put the
unwindHeader at offset 0x58 in __cxa_exception, but it requires 16-byte
alignment. In order to avoid changing the current __cxa_exception ABI
(and thus breaking its consumers), add explicit padding in the
allocation routines (and account for it when freeing).

This is intended as a lower-risk change for FreeBSD 11. A "more correct"
fix should be prepared for upstream and -CURRENT.

Reviewed by: dim
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D7271

MFC r305396:

Add _US_ACTION_MASK to libcxxrt's arm-specific unwind header. This
value is used in newer versions of compiler-rt.

MFC r314061:

Add __int128-related symbols to libcxxrt's version map. Put these into
the same CXXABI verions as recent libstdc++.

Note that __int128 types are only available on arches where long long is
128 bit wide.

Noticed by: harti

MFC r314104:

Surround any unmangled C++ names in libcxxrt's version map with 'extern
"C++"', otherwise ld refuses to make the symbols global in the final
library. This causes the __int128-related symbols to go missing when
the library is stripped during installation.

Helpful hints: emaste

MFC r312504:

Use SRCTOP-relative paths to other directories instead of .CURDIR-relative ones

This simplifies pathing in make/displayed output

MFC r302278: libcxxrt: correct mangled "typeinfo name" symbols in Version.map

r261644 (MFC of r260553) added missing C++ typinfos to libcxxrt's
version script. It appears that a number of duplicate mangled symbols
were added due to a cut and paste error. Switch the second instances to
_ZTS*, typeinfo name for *.

Found by lld, which produces an error or warning for duplicate symbols.

Sponsored by: The FreeBSD Foundation

MFC r284732:

Add __cxa_deleted_virtual to libcxxrt's version map.

This symbol can sometimes be emitted by clang++, and was not yet
exported from libcxxrt. Attempt to be compatible with libsupc++ by
using the same CXXABI_1.3.6 symbol version.

Approved by: re (kib)
Reported by: yuri@rawbw.com
PR: 200863
Reviewed by: emaste
Differential Revision: https://reviews.freebsd.org/D2850

Synchronize the default C++ stack in stable/10 with head, by merging
almost all recent changes to libc++ and libcxxrt.

MFC r256642:
Since C++ typeinfo objects are currently not guaranteed to be merged at
runtime by the dynamic linker, check for their equality in libcxxrt by
not only comparing the typeinfo's name pointers, but also comparing the
full names, if necessary. (This is similar to what GNU libstdc++ does
in its default configuration.) The 'deep' check can be turned off again
by defining LIBCXXRT_MERGED_TYPEINFO, and recompiling libcxxrt.

Reviewed by: theraven

MFC r270522 (by rdivacky):
The standard we compile libc++ with is called c++11 not c++0x.

MFC r273066 (by bapt):
Import patch from libc++ r197313 which allows using libc++ headers with gcc

Differential Revision: https://reviews.freebsd.org/D942
Reviewed by: imp

MFC r273381 (by bapt):
Add support for __cxa_throw_bad_array_new_length in libcxxrt

It is required for use with newer g++49

Differential Revision: https://reviews.freebsd.org/D982
Reviewed by: theraven
Approved by: theraven

MFC r273382 (by bapt):
Fix build by marking the new functions as weak
This is a temporary fix

MFC r273407 (by bapt):
When using an external gcc 4.8+ and not building libstdc++ then create in the objectdir a
fake libstdc++.so and libstdc++.a which is a symlink on libc++ that allow g++ to satisfy
its links dependencies in the least hackish way.
Please note that this hacky libstds++ never get installed on the final system

Reviewed by: imp

MFC r273434 (by bapt):
Do not define bad_array_new_length::bad_array_new_length in libc++ anymore
when used in combinaison with libcxxrt since it is now defined there already.
This fixes building world

MFC r276417:
Import libcxxrt master 00bc29eb6513624824a6d7db2ebc768a4216a604.

Interesting fixes:
76584a0 Reorganize code to use only 32bit atomic ops for 32bit platforms
30d2ae5 Implement __cxa_throw_bad_array_new_length

Reviewed by: bapt
Differential Revision: https://reviews.freebsd.org/D1390

MFC r277217:
Import libc++ trunk r224926. This fixes a number of bugs, completes
C++14 support[1], adds more C++1z features[2], and fixes the following
LWG issues[3]:

1450: Contradiction in regex_constants
2003: String exception inconsistency in erase.
2075: Progress guarantees, lock-free property, and scheduling
assumptions
2104: unique_lock move-assignment should not be noexcept
2112: User-defined classes that cannot be derived from
2132: std::function ambiguity
2135: Unclear requirement for exceptions thrown in
condition_variable::wait()
2142: packaged_task::operator() synchronization too broad?
2182: Container::[const_]reference types are misleadingly specified
2186: Incomplete action on async/launch::deferred
2188: Reverse iterator does not fully support targets that overload
operator&
2193: Default constructors for standard library containers are explicit
2205: Problematic postconditions of regex_match and regex_search
2213: Return value of std::regex_replace
2240: Probable misuse of term "function scope" in [thread.condition]
2252: Strong guarantee on vector::push_back() still broken with C++11?
2257: Simplify container requirements with the new algorithms
2258: a.erase(q1, q2) unable to directly return q2
2263: Comparing iterators and allocator pointers with different
const-character
2268: Setting a default argument in the declaration of a member
function assign of std::basic_string
2271: regex_traits::lookup_classname specification unclear
2272: quoted should use char_traits::eq for character comparison
2278: User-defined literals for Standard Library types
2280: begin / end for arrays should be constexpr and noexcept
2285: make_reverse_iterator
2288: Inconsistent requirements for shared mutexes
2291: std::hash is vulnerable to collision DoS attack
2293: Wrong facet used by num_put::do_put
2299: Effects of inaccessible key_compare::is_transparent type are not
clear
2301: Why is std::tie not constexpr?
2304: Complexity of count in unordered associative containers
2306: match_results::reference should be value_type&, not const
value_type&
2308: Clarify container destructor requirements w.r.t. std::array
2313: tuple_size should always derive from integral_constant<size_t, N>
2314: apply() should return decltype(auto) and use decay_t before
tuple_size
2315: weak_ptr should be movable
2316: weak_ptr::lock() should be atomic
2317: The type property queries should be UnaryTypeTraits returning
size_t
2320: select_on_container_copy_construction() takes allocators, not
containers
2322: Associative(initializer_list, stuff) constructors are
underspecified
2323: vector::resize(n, t)'s specification should be simplified
2324: Insert iterator constructors should use addressof()
2329: regex_match()/regex_search() with match_results should forbid
temporary strings
2330: regex("meow", regex::icase) is technically forbidden but should
be permitted
2332: regex_iterator/regex_token_iterator should forbid temporary
regexes
2339: Wording issue in nth_element
2341: Inconsistency between basic_ostream::seekp(pos) and
basic_ostream::seekp(off, dir)
2344: quoted()'s interaction with padding is unclear
2346: integral_constant's member functions should be marked noexcept
2350: min, max, and minmax should be constexpr
2356: Stability of erasure in unordered associative containers
2357: Remaining "Assignable" requirement
2359: How does regex_constants::nosubs affect basic_regex::mark_count()?
2360: reverse_iterator::operator*() is unimplementable

[1] http://libcxx.llvm.org/cxx1y_status.html
[2] http://libcxx.llvm.org/cxx1z_status.html
[3] http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html

Exp-run: antoine

MFC r277944:
Partially revert r273382, to reduce diffs against upstream. This was a
temporary fix to solve a conflict with an older version of libc++, and
it is no longer relevant.

MFC r278010:
Revert r256642, not only to reduce diffs against upstream libcxxrt, but
also because it is the wrong approach: comparing typeinfo names deeply
causes trouble if two loaded DSOs use independent types of the same
name.

In addition, this particular change was never merged to FreeBSD 10.x and
9.x, so let's get rid of it before it ends up in an 11.x release.

Discussed with: theraven, joerg@netbsd

MFC r278016:
Import libcxxrt master 1cb607e89f6135bbc10f3d3b6fba1f983e258dcc.

Interesting fixes:
1cb607e Correct gcc version check for __cxa_begin_catch() declaration
with or without throw()

Revert r278017 (MFC of r273381 and r276417) and r278018 (MFC of r273434)
until I can figure out why it leads to link failures in some scenarios.

MFC r273381 (by bapt):

Add support for __cxa_throw_bad_array_new_length in libcxxrt

It is required for use with newer g++49

Differential Revision: https://reviews.freebsd.org/D982
Reviewed by: theraven
Approved by: theraven

MFC r276417:

Import libcxxrt master 00bc29eb6513624824a6d7db2ebc768a4216a604.

Interesting fixes:
76584a0 Reorganize code to use only 32bit atomic ops for 32bit platforms
30d2ae5 Implement __cxa_throw_bad_array_new_length

Reviewed by: bapt
Differential Revision: https://reviews.freebsd.org/D1390

MFC r260553 (by theraven):

Add missing C++11 typeinfos to the libcxxrt version script.

PR: 185663

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

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

Add several missing symbols to libcxxrt's symbol version map, and remove
a few duplicates. This should fix building world with -stdlib=libc++
after r246028.

Submitted by: Yamaya Takashi <yamayan@kbh.biglobe.ne.jp>
MFC after: 1 week
X-MFC-With: r246028

Fix some symbol version mismatches between libstdc++ and libsupc++/libcxxrt
that were causing the runtime and STL libraries to see different versions of
various classes and functions when libstdc++ is used as a filter.

Note: This changes the ABI for libcxxrt, but libcxxrt is currently only in
-STABLE for testing and is not used by anything unless explicitly enabled by
the end user. No default compiler configurations use it.

libc++ will need to be recompiled after this change. make buildworld will do
this automatically, but make in lib/libc++ will not necessarily work unless the
new libcxxrt is installed first.

PR: kern/171610, stand/175453
Reviewed by: kib
MFC after: 1 week

Clean up some symbol versions for libsupc++ / libcxxrt.

MFC after: 1 week
Reviewed by: kan

Tabify libcxxrt and libc++'s Makefiles.

MFC after: 3 days

Import new version of libcxxrt. Now works correctly with libobjc2 to implement
the unified exception model for Objective-C++.

Approved by: dim (mentor)

Add symbol versioning to libcxxrt.

Approved by: dim (mentor)

Update libcxxrt to remove the pthread dependency.

Also add the license from upstream to contrib.

Approved by: dim (mentor)

Import libc++ / libcxxrt into base. Not build by default yet (use
MK_LIBCPLUSPLUS=yes to enable). This is a work-in-progress. It works for
me, but is not guaranteed to work for anyone else and may eat your dog.

To build C++ using libc++, add -stdlib=libc++ to your CXX and LD flags.

Bug reports welcome, bug fixes even more welcome...

Approved by: dim (mentor)