[clang] [llvm] Deprecate the `-fbasic-block-sections=labels` option. (PR #107494)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-aarch64-darwin` running on `doug-worker-5` while building `clang,llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/190/builds/6519

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 5 (build-unified-tree) failure: build (failure)
...
200.835 [3413/8/2450] Generating ../../bin/llvm-dlltool
201.323 [3412/8/2451] Linking CXX executable bin/llvm-lto
201.342 [3411/8/2452] Linking CXX static library lib/liblldCOFF.a
201.365 [3410/8/2453] Building CXX object tools/lld/MachO/CMakeFiles/lldMachO.dir/MapFile.cpp.o
201.390 [3409/8/2454] Building CXX object tools/lld/MachO/CMakeFiles/lldMachO.dir/MarkLive.cpp.o
201.419 [3408/8/2455] Building CXX object tools/lld/MachO/CMakeFiles/lldMachO.dir/ObjC.cpp.o
201.442 [3407/8/2456] Building CXX object tools/lld/MachO/CMakeFiles/lldMachO.dir/OutputSection.cpp.o
201.467 [3406/8/2457] Building CXX object tools/lld/MachO/CMakeFiles/lldMachO.dir/OutputSegment.cpp.o
201.493 [3405/8/2458] Building CXX object tools/lld/MachO/CMakeFiles/lldMachO.dir/Relocations.cpp.o
201.497 [3404/8/2459] Building CXX object tools/lld/ELF/CMakeFiles/lldELF.dir/LTO.cpp.o
FAILED: tools/lld/ELF/CMakeFiles/lldELF.dir/LTO.cpp.o 
CCACHE_CPP2=yes CCACHE_HASHDIR=yes /opt/homebrew/bin/ccache /usr/bin/clang++ -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GLIBCXX_ASSERTIONS -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/Users/buildbot/buildbot-root/aarch64-darwin/build/tools/lld/ELF -I/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/lld/ELF -I/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/lld/include -I/Users/buildbot/buildbot-root/aarch64-darwin/build/tools/lld/include -I/Users/buildbot/buildbot-root/aarch64-darwin/build/include -I/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/include -isystem /opt/homebrew/include -fPIC -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -O3 -DNDEBUG -std=c++17 -arch arm64 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX14.4.sdk  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -MD -MT tools/lld/ELF/CMakeFiles/lldELF.dir/LTO.cpp.o -MF tools/lld/ELF/CMakeFiles/lldELF.dir/LTO.cpp.o.d -o tools/lld/ELF/CMakeFiles/lldELF.dir/LTO.cpp.o -c /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/lld/ELF/LTO.cpp
/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/lld/ELF/LTO.cpp:74:49: error: no member named 'Labels' in 'llvm::BasicBlockSection'
      c.Options.BBSections = BasicBlockSection::Labels;
                             ~~~~~~~~~~~~~~~~~~~^
1 error generated.
201.520 [3404/7/2460] Building CXX object tools/lld/MachO/CMakeFiles/lldMachO.dir/BPSectionOrderer.cpp.o
203.550 [3404/6/2461] Building CXX object tools/lld/MachO/CMakeFiles/lldMachO.dir/DriverUtils.cpp.o
204.169 [3404/5/2462] Building CXX object tools/lld/ELF/CMakeFiles/lldELF.dir/InputFiles.cpp.o
204.212 [3404/4/2463] Building CXX object tools/lld/MachO/CMakeFiles/lldMachO.dir/LTO.cpp.o
204.521 [3404/3/2464] Building CXX object tools/lld/ELF/CMakeFiles/lldELF.dir/Driver.cpp.o
205.050 [3404/2/2465] Building CXX object tools/lld/MachO/CMakeFiles/lldMachO.dir/Driver.cpp.o
205.835 [3404/1/2466] Building CXX object tools/lld/MachO/CMakeFiles/lldMachO.dir/InputFiles.cpp.o
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/107494