Remove $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

Move LIBADD lines from usr.bin/clang/*/Makefile one level up

Some utilities under usr.bin/clang were only linked to libz, while most
others were linked to libz and libzstd. Make this consistent, and remove
repetition, by moving these LIBADD lines to usr.bin/clang/clang.prog.mk
and usr.bin/clang/clang.prog.mk.

MFC after: 3 days

Merge llvm-project release/16.x llvmorg-16.0.1-0-gcd89023f7979

This updates llvm, clang, compiler-rt, libc++, libunwind, lld, lldb and
openmp to llvmorg-16.0.1-0-gcd89023f7979 (aka 16.0.1 release).

PR: 271047
MFC after: 1 month

remove GCC 4.2.1 build infrastructure

As described in Warner's email message[1] to the FreeBSD-arch mailing
list we have reached GCC 4.2.1's retirement date. At this time all
supported architectures either use in-tree Clang, or rely on external
toolchain (i.e., a contemporary GCC version from ports).

GCC 4.2.1 was released July 18, 2007 and was imported into FreeBSD later
that year, in r171825. GCC has served us well, but version 4.2.1 is
obsolete and not used by default on any architecture in FreeBSD. It
does not support modern C and does not support arm64 or RISC-V.

Thanks to everyone responsible for maintaining, updating, and testing
GCC in the FreeBSD base system over the years.

So long, and thanks for all the fish.

[1] https://lists.freebsd.org/pipermail/freebsd-arch/2020-January/019823.html

PR: 228919
Reviewed by: brooks, imp
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D23124

Move all sources from the llvm project into contrib/llvm-project.

This uses the new layout of the upstream repository, which was recently
migrated to GitHub, and converted into a "monorepo". That is, most of
the earlier separate sub-projects with their own branches and tags were
consolidated into one top-level directory, and are now branched and
tagged together.

Updating the vendor area to match this layout is next.

Update llvm and clang build glue to make MK_CLANG_EXTRAS=yes and
MK_CLANG_FULL=yes work.

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
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17923

Update llvm-cov and llvm-pdbdump Makefiles.

Completely revamp the way llvm, clang and lldb are built.

* Bootstrap llvm-tblgen and clang-tblgen with a minimal llvm static
library, that has no other dependencies.
* Roll up all separate llvm libraries into one big static libllvm.
* Similar for all separate clang and lldb static libraries.
* For all these libraries, generate their .inc files only once.
* Link all llvm tools (including extra) against the big libllvm.
* Link clang and clang-format against the big libllvm and libclang.
* Link lldb against the big libllvm, libclang and liblldb.

N.B.: This is work in progress, some details may still be missing.

It also heavily depends on bsd.*.mk's support for SRCS and DPSRCS with
relative pathnames, which apparently does not always work as expected.
For building llvm, clang and lldb though, it seems to work just fine.

The main idea behind this restructuring is maintainability and build
peformance. The previous large number of very small libraries, each
with their own generated files and dependencies was slow to traverse
and hard to understand.

Possible future improvements:
* Only build certain targets, e.g. for most regular users having just
one target will be fine. This will shave off some build time.
* Building the big llvm, clang and lldb libraries as shared (private)
libraries.
* Adding other components from the LLVM project, such as lld.

Update build glue for clang and the llvm/clang extras.

Some additional llvm tools need libz. While here, consistently use
LIBADD+=.

Update Makefiles and other build glue for llvm/clang 3.7.0, as of trunk
r238337.

Add the llvm-cov and llvm-profdata tools, when WITH_CLANG_EXTRAS is
defined. These help with processing coverage and profile data.

remove GCC 4.2.1 build infrastructure

As described in Warner's email message[1] to the FreeBSD-arch mailing
list we have reached GCC 4.2.1's retirement date. At this time all
supported architectures either use in-tree Clang, or rely on external
toolchain (i.e., a contemporary GCC version from ports).

GCC 4.2.1 was released July 18, 2007 and was imported into FreeBSD later
that year, in r171825. GCC has served us well, but version 4.2.1 is
obsolete and not used by default on any architecture in FreeBSD. It
does not support modern C and does not support arm64 or RISC-V.

Thanks to everyone responsible for maintaining, updating, and testing
GCC in the FreeBSD base system over the years.

So long, and thanks for all the fish.

[1] https://lists.freebsd.org/pipermail/freebsd-arch/2020-January/019823.html

PR: 228919
Reviewed by: brooks, imp
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D23124

Move all sources from the llvm project into contrib/llvm-project.

This uses the new layout of the upstream repository, which was recently
migrated to GitHub, and converted into a "monorepo". That is, most of
the earlier separate sub-projects with their own branches and tags were
consolidated into one top-level directory, and are now branched and
tagged together.

Updating the vendor area to match this layout is next.

Update llvm and clang build glue to make MK_CLANG_EXTRAS=yes and
MK_CLANG_FULL=yes work.

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
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17923

Update llvm-cov and llvm-pdbdump Makefiles.

Completely revamp the way llvm, clang and lldb are built.

* Bootstrap llvm-tblgen and clang-tblgen with a minimal llvm static
library, that has no other dependencies.
* Roll up all separate llvm libraries into one big static libllvm.
* Similar for all separate clang and lldb static libraries.
* For all these libraries, generate their .inc files only once.
* Link all llvm tools (including extra) against the big libllvm.
* Link clang and clang-format against the big libllvm and libclang.
* Link lldb against the big libllvm, libclang and liblldb.

N.B.: This is work in progress, some details may still be missing.

It also heavily depends on bsd.*.mk's support for SRCS and DPSRCS with
relative pathnames, which apparently does not always work as expected.
For building llvm, clang and lldb though, it seems to work just fine.

The main idea behind this restructuring is maintainability and build
peformance. The previous large number of very small libraries, each
with their own generated files and dependencies was slow to traverse
and hard to understand.

Possible future improvements:
* Only build certain targets, e.g. for most regular users having just
one target will be fine. This will shave off some build time.
* Building the big llvm, clang and lldb libraries as shared (private)
libraries.
* Adding other components from the LLVM project, such as lld.

Update build glue for clang and the llvm/clang extras.

Some additional llvm tools need libz. While here, consistently use
LIBADD+=.

Update Makefiles and other build glue for llvm/clang 3.7.0, as of trunk
r238337.