[libc] [llvm] [LLVM] Make the GPU loader utilities an LLVM tool (PR #132096)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `flang-aarch64-libcxx` running on `linaro-flang-aarch64-libcxx` while building `libc,llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/89/builds/19091

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
  138 |     report_error(std::move(elf_or_err.takeError()));
      |                  ^
../llvm-project/llvm/tools/llvm-gpu-loader/llvm-gpu-loader.cpp:138:18: note: remove std::move call here
  138 |     report_error(std::move(elf_or_err.takeError()));
      |                  ^~~~~~~~~~                      ~
../llvm-project/llvm/tools/llvm-gpu-loader/llvm-gpu-loader.cpp:132:20: warning: unused variable 'params' [-Wunused-variable]
  132 |   LaunchParameters params{threads_x, threads_y, threads_z,
      |                    ^~~~~~
7 warnings generated.
60.806 [186/3/7213] Linking CXX executable bin/llvm-gpu-loader
FAILED: bin/llvm-gpu-loader 
: && /usr/local/bin/c++ -stdlib=libc++ -fPIC -fno-semantic-interposition -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 -ffunction-sections -fdata-sections -O3 -DNDEBUG -stdlib=libc++     -Wl,-rpath-link,/home/tcwg-buildbot/worker/flang-aarch64-libcxx/build/./lib  -Wl,--gc-sections tools/llvm-gpu-loader/CMakeFiles/llvm-gpu-loader.dir/llvm-gpu-loader.cpp.o -o bin/llvm-gpu-loader  -Wl,-rpath,"\$ORIGIN/../lib:/home/tcwg-buildbot/worker/flang-aarch64-libcxx/build/lib:"  lib/libLLVMOption.so.21.0git  lib/libLLVMFrontendOffloading.so.21.0git  lib/libLLVMObject.so.21.0git  lib/libLLVMBinaryFormat.so.21.0git  lib/libLLVMSupport.so.21.0git  -Wl,-rpath-link,/home/tcwg-buildbot/worker/flang-aarch64-libcxx/build/lib && :
/usr/bin/ld: tools/llvm-gpu-loader/CMakeFiles/llvm-gpu-loader.dir/llvm-gpu-loader.cpp.o: undefined reference to symbol '_ZN4llvm6Triple15getArchTypeNameENS0_8ArchTypeE'
/usr/bin/ld: /home/tcwg-buildbot/worker/flang-aarch64-libcxx/build/./lib/libLLVMTargetParser.so.21.0git: error adding symbols: DSO missing from command line
clang++: error: linker command failed with exit code 1 (use -v to see invocation)
61.972 [186/2/7214] Linking CXX shared library lib/libFortranEvaluate.so.21.0git
116.216 [186/1/7215] Building CXX object tools/flang/lib/Frontend/CMakeFiles/flangFrontend.dir/cmake_pch.hxx.pch
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/132096