Merge llvm, clang, compiler-rt, libc++, libunwind, lld, lldb and openmp

Merge llvm, clang, compiler-rt, libc++, libunwind, lld, lldb and openmp
8.0.0 final release r356365.

MFC r340287 (by emaste):

Consolidate gcov entries in OptionalObsoleteFiles

Sponsored by:	The FreeBSD Foundation

MFC r340289 (by emaste):

llvm-cov: also install as gcov (if GNU gcov is disabled)

llvm-cov provides a gcov-compatible interface when invoked as gcov.

Reviewed by:	dim, markj
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D17923

MFC r340296 (by emaste):

Move llvm-profdata build into MK_LLVM_COV block

llvm-profdata is used with llvm-cov for code coverage (although llvm-cov
can also operate independently in a gcov-compatible mode).
Although llvm-profdata can be used independently of llvm-cov it makes
sense to group these under one option.

Also handle these in OptionalObsoleteFiles.inc while here.

Sponsored by:	The FreeBSD Foundation

MFC r340300 (by emaste):

libllvm: Move SampleProfWriter to SRCS_MIN

It is required by llvm-profdata, now built by default under the
LLVM_COV knob.  The additional complexity that would come from avoiding
building it if CLANG_EXTRAS and LLVM_COV are both disabled is not worth
the small savings in build time.

Sponsored by:	The FreeBSD Foundation

MFC r340972 (by emaste):

llvm-objdump: initial man page

Based on llvm-objdump's online documentation and usage information.
This serves as a starting point; additional detail and cleanup still
required.

Also being submitted upstream in LLVM review D54864.  I expect to use
this bespoke copy while we have LLVM 6.0 or 7.0 in FreeBSD; when we
update to LLVM 8.0 it should be upstream and we will switch to it.

PR:		233437
Reviewed by:	bcr (man formatting)
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D18309

MFC r340973 (by emaste):

llvm-objdump.1: remove invalid options

Some options appear in llvm-objdump's usage information as a side effect
of its option parsing implementation and are not actually llvm-objdump
options.  Reported in LLVM review https://reviews.llvm.org/D54864.

Reported by:	Fangrui Song
Sponsored by:	The FreeBSD Foundation

MFC r340975 (by emaste):

llvm-objdump.1: fix igor / mandoc -Tlint warnings

Accidentally omitted from r340972.

MFC r341055 (by emaste):

llvm-objdump.1: remove more unintentional options

Some options come from static constructors in LLVM libraries and are
automatically added to llvm's usage output.  They're not really supposed
to be llvm-objdump options.

Reported by:	Fangrui Song in LLVM review D54864
Sponsored by:	The FreeBSD Foundation

MFC r344779:

Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
the upstream release_80 branch r355313 (effectively, 8.0.0 rc3).  The
release will follow very soon, but no more functional changes are
expected.

Release notes for llvm, clang and lld 8.0.0 will soon be available here:
<https://releases.llvm.org/8.0.0/docs/ReleaseNotes.html>
<https://releases.llvm.org/8.0.0/tools/clang/docs/ReleaseNotes.html>
<https://releases.llvm.org/8.0.0/tools/lld/docs/ReleaseNotes.html>

PR:		236062
Relnotes:	yes

MFC r344798 (by emaste):

libllvm: promote WithColor and xxhash to SRCS_MIN

The armv6 build failed in CI due to missing symbols (from these two
source files) in the bootstrap Clang.

This affected only armv6 because other Clang-using archs are using LLD
as the bootstrap linker, and thus include SRCS_MIW via LLD_BOOTSTRAP.

Reported by:	CI, via lwhsu
Sponsored by:	The FreeBSD Foundation

MFC r344825:

Add a few missed files to the MK_LLVM_TARGET_BPF=yes case, otherwise
clang and various other executables will fail to link with undefined
symbols.

Reported by:	O. Hartmann <ohartmann@walstatt.org>

MFC r344852:

Put in a temporary workaround for what is likely a gcc 6 bug (it does
not occur with gcc 7 or later).  This should prevent the following error
from breaking the head-amd64-gcc CI builds:

In file included from /workspace/src/contrib/llvm/tools/lldb/source/API/SBMemoryRegionInfo.cpp:14:0:
/workspace/src/contrib/llvm/tools/lldb/include/lldb/Target/MemoryRegionInfo.h:128:54: error: 'template<class _InputIterator> lldb_private::MemoryRegionInfos::MemoryRegionInfos(_InputIterator, _InputIterator, const allocator_type&)' inherited from 'std::__1::vector<lldb_private::MemoryRegionInfo>'
   using std::vector<lldb_private::MemoryRegionInfo>::vector;
                                                      ^~~~~~
/workspace/src/contrib/llvm/tools/lldb/include/lldb/Target/MemoryRegionInfo.h:128:54: error: conflicts with version inherited from 'std::__1::vector<lldb_private::MemoryRegionInfo>'

Reported by:	CI

MFC r344896:

Pull in r354937 from upstream clang trunk (by Jörg Sonnenberger):

  Fix inline assembler constraint validation

  The current constraint logic is both too lax and too strict. It fails
  for input outside the [INT_MIN..INT_MAX] range, but it also
  implicitly accepts 0 as value when it should not. Adjust logic to
  handle both correctly.

  Differential Revision: https://reviews.llvm.org/D58649

Pull in r355491 from upstream clang trunk (by Hans Wennborg):

  Inline asm constraints: allow ICE-like pointers for the "n"
  constraint (PR40890)

  Apparently GCC allows this, and there's code relying on it (see bug).

  The idea is to allow expression that would have been allowed if they
  were cast to int. So I based the code on how such a cast would be
  done (the CK_PointerToIntegral case in
  IntExprEvaluator::VisitCastExpr()).

  Differential Revision: https://reviews.llvm.org/D58821

These should fix assertions and errors when using the inline assembly
"n" constraint in certain ways.

In case of devel/valgrind, a pointer was used as the input for the
constraint, which lead to "Assertion failed: (isInt() && "Invalid
accessor"), function getInt".

In case of math/secp256k1, a very large integer value was used as input
for the constraint, which lead to "error: value '4624529908474429119'
out of range for constraint 'n'".

PR:             236216, 236194

MFC r344951:

Merge llvm, clang, compiler-rt, libc++, lld, and lldb release_80 branch
r355677 (effectively, 8.0.0 rc4), resolve conflicts, and bump version
numbers.

PR:		236062

MFC r345018:

Merge LLVM libunwind trunk r351319, from just before upstream's
release_80 branch point.  Afterwards, we will merge the rest of the
changes in the actual release_80 branch.

PR:		236062

MFC r345019:

Merge LLVM libunwind release_80 branch r355677 (effectively, 8.0.0 rc4).

PR:		236062

MFC r345021:

Pull in r355854 from upstream llvm trunk (by Jonas Paulsson):

  [RegAlloc]  Avoid compile time regression with multiple copy hints.

  As a fix for https://bugs.llvm.org/show_bug.cgi?id=40986 ("excessive
  compile time building opencollada"), this patch makes sure that no
  phys reg is hinted more than once from getRegAllocationHints().

  This handles the case were many virtual registers are assigned to the
  same physreg. The previous compile time fix (r343686) in
  weightCalcHelper() only made sure that physical/virtual registers are
  passed no more than once to addRegAllocationHint().

  Review: Dimitry Andric, Quentin Colombet
  https://reviews.llvm.org/D59201

This should fix a hang when compiling certain generated .cpp files in
the graphics/opencollada port.

PR:		236313

MFC r345068 (by jhb):

Move libunwind out of contrib/llvm/projects.

Move LLVM's libunwind to its own contrib/ directory similar to other
runtime libraries like libc++ and libcxxrt.

Reviewed by:	dim, emaste
Differential Revision:	https://reviews.freebsd.org/D19534

MFC r345073:

Revert r308867 (which was originally committed in the clang390-import
project branch):

  Work around LLVM PR30879, which is about a bad interaction between
  X86 Call Frame Optimization on i386 and libunwind, by disallowing the
  optimization for i386-freebsd12.

  This should fix some instances of broken exception handling when
  frame pointers are omitted, in particular some unittests run during
  the build of editors/libreoffice.

  This hack will be removed as soon as upstream has implemented a more
  permanent fix for this problem.

And indeed, after r345018 and r345019, which updated LLVM libunwind to
the most recent version, the above workaround is no longer needed.  The
upstream commit which fixed this is:

  https://llvm.org/viewvc/llvm-project?view=revision&revision=292723

Specifically, 32 bit (i386-freebsd) executables optimized with omitted
frame pointers and Call Frame Optimization should now behave correctly
when a C++ exception is thrown, and the stack is unwound.

Upstream PR:	https://llvm.org/bugs/show_bug.cgi?id=30879
PR:		236062

MFC r345152:

Merge llvm, clang, compiler-rt, libc++, libunwind, lld, and lldb
release_80 branch r356034 (effectively, 8.0.0 rc5), resolve conflicts,
and bump version numbers.

PR:		236062

MFC r345231:

Add LLVM openmp trunk r351319 (just before the release_80 branch point)
to contrib/llvm.  This is not yet connected to the build, the glue for
that will come in a follow-up commit.

PR:		236062

MFC r345232:

Bootstrap svn:mergeinfo on contrib/openmp.

PR:		236062

MFC r345233:

Merge openmp release_80 branch r356034 (effectively, 8.0.0 rc5).

PR:		236062

MFC r345234:

Add openmp __kmp_gettid() wrapper, using pthread_getthreadid_np(3).
This has also been submitted upstream.

PR:           236062

MFC r345283:

Enable building libomp.so for 32-bit x86.  This is done by selectively
enabling the functions that save and restore MXCSR, since access to this
register requires SSE support.

Note that you may run into other issues with OpenMP on i386, since this
*not* yet supported upstream, and certainly not extensively tested.

PR:		236062, 236582

MFC r345345:

Merge llvm, clang, compiler-rt, libc++, libunwind, lld, lldb and openmp
8.0.0 final release r356365.  There were no functional changes since the
most recent merge, of 8.0.0 rc5.

Release notes for llvm, clang, lld and libc++ 8.0.0 are now available:

https://llvm.org/releases/8.0.0/docs/ReleaseNotes.html
https://llvm.org/releases/8.0.0/tools/clang/docs/ReleaseNotes.html
https://llvm.org/releases/8.0.0/tools/lld/docs/ReleaseNotes.html
https://llvm.org/releases/8.0.0/projects/libcxx/docs/ReleaseNotes.html

PR:		236062

MFC r345349:

Pull in r352826 from upstream lld trunk (by Fangrui Song):

  [ELF] Support --{,no-}allow-shlib-undefined

  Summary:
  In ld.bfd/gold, --no-allow-shlib-undefined is the default when
  linking an executable. This patch implements a check to error on
  undefined symbols in a shared object, if all of its DT_NEEDED entries
  are seen.

  Our approach resembles the one used in gold, achieves a good balance
  to be useful but not too smart (ld.bfd traces all DSOs and emulates
  the behavior of a dynamic linker to catch more cases).

  The error is issued based on the symbol table, different from
  undefined reference errors issued for relocations. It is most
  effective when there are DSOs that were not linked with -z defs (e.g.
  when static sanitizers runtime is used).

  gold has a comment that some system libraries on GNU/Linux may have
  spurious undefined references and thus system libraries should be
  excluded (https://sourceware.org/bugzilla/show_bug.cgi?id=6811). The
  story may have changed now but we make --allow-shlib-undefined the
  default for now. Its interaction with -shared can be discussed in the
  future.

  Reviewers: ruiu, grimar, pcc, espindola

  Reviewed By: ruiu

  Subscribers: joerg, emaste, arichardson, llvm-commits

  Differential Revision: https://reviews.llvm.org/D57385

Pull in r352943 from upstream lld trunk (by Fangrui Song):

  [ELF] Default to --no-allow-shlib-undefined for executables

  Summary:
  This follows the ld.bfd/gold behavior.

  The error check is useful as it captures a common type of ld.so
  undefined symbol errors as link-time errors:

      // a.cc => a.so (not linked with -z defs)
      void f(); // f is undefined
      void g() { f(); }

      // b.cc => executable with a DT_NEEDED entry on a.so
      void g();
      int main() { g(); }

      // ld.so errors when g() is executed (lazy binding) or when the program is started (-z now)
      // symbol lookup error: ... undefined symbol: f

  Reviewers: ruiu, grimar, pcc, espindola

  Reviewed By: ruiu

  Subscribers: llvm-commits, emaste, arichardson

  Tags: #llvm

  Differential Revision: https://reviews.llvm.org/D57569

Together, these add support for --no-allow-shlib-undefined, and make it
the default for executables, so they will fail to link if any symbols
from needed shared libraries are undefined.

Reported by:	jbeich
PR:		236062, 236141

MFC r345449:

Pull in r356809 from upstream llvm trunk (by Eli Friedman):

  [ARM] Don't form "ands" when it isn't scheduled correctly.

  In r322972/r323136, the iteration here was changed to catch cases at
  the beginning of a basic block... but we accidentally deleted an
  important safety check.  Restore that check to the way it was.

  Fixes https://bugs.llvm.org/show_bug.cgi?id=41116

  Differential Revision: https://reviews.llvm.org/D59680

This should fix "Assertion failed: (LiveCPSR && "CPSR liveness tracking
is wrong!"), function UpdateCPSRUse" errors when building the devel/xwpe
port for armv7.

PR:		236062, 236568