MFC r348504 (by kevans):

MFC r348504 (by kevans):

llvm-symbolizer: Move out of CLANG_EXTRAS, into CLANG

ASAN reports become a lot more useful with llvm-symbolizer in $PATH, and the
build is not much more time-consuming. The added benefit is that the
resulting reports will actually include symbol information; without, thread
trace information includes a bunch of addresses that immediately resolve to
an inline function in
^/contrib/compiler-rt/lib/sanitizer_common/sanitizer_common.h and take a
little more effort to examine.

Reviewed by:	emaste
Differential Revision:	https://reviews.freebsd.org/D20484

MFC r349004:

Upgrade our copies of clang, llvm, lld, lldb, compiler-rt, libc++,
libunwind and openmp to the upstream release_80 branch r363030
(effectively, 8.0.1 rc2).  The 8.0.1 release should follow this within a
week or so.

MFC r349351 (by jhibbits, partially):

powerpc: Transition to Secure-PLT, like most other OSs (Toolchain part)

Summary:
Toolchain follow-up to r349350.  LLVM patches will be submitted upstream for
9.0 as well.

The bsd.cpu.mk change is required because GNU ld assumes BSS-PLT if it
cannot determine for certain that it needs Secure-PLT, and some binaries do
not compile in such a way to make it know to use Secure-PLT.

Reviewed By: nwhitehorn, bdragon, pfg
Differential Revision: https://reviews.freebsd.org/D20598

MFC r349793:

Upgrade our copies of clang, llvm, lld, lldb, compiler-rt, libc++,
libunwind and openmp to the upstream release_80 branch r364487
(effectively, 8.0.1 rc3).  The 8.0.1 release will most likely
have no further changes.

MFC r350177:

Merge llvm, clang, compiler-rt, libc++, libunwind, lld, lldb and openmp
8.0.1 final release r366581.  The only functional change is a fix for a
mismerge of upstream r360816, which properly restores the r2 register
when unwinding on PowerPC64 (See https://reviews.freebsd.org/D20337).

Relnotes:	yes
PR:		236062