[clang] [amdgpu-arch] Replace use of HSA with reading sysfs directly (PR #116651)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-ppc64-aix` running on `aix-ppc64` while building `clang` at step 3 "clean-build-dir".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/64/builds/1492

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

```
Step 3 (clean-build-dir) failure: Delete failed. (failure) (timed out)
Step 5 (build-unified-tree) failure: build (failure)
...
6066.097 [533/10/4667] Building CXX object tools/clang/tools/libclang/CMakeFiles/libclang.dir/CIndexInclusionStack.cpp.o
6067.313 [532/10/4668] Building CXX object tools/clang/tools/libclang/CMakeFiles/libclang.dir/CXCursor.cpp.o
6071.142 [531/10/4669] Linking CXX executable bin/clang-offload-packager
6071.391 [530/10/4670] Building CXX object tools/clang/tools/libclang/CMakeFiles/libclang.dir/CIndex.cpp.o
6071.498 [529/10/4671] Building CXX object tools/clang/tools/libclang/CMakeFiles/libclang.dir/CXIndexDataConsumer.cpp.o
6071.666 [528/10/4672] Building CXX object tools/clang/tools/libclang/CMakeFiles/libclang.dir/FatalErrorHandler.cpp.o
6072.379 [527/10/4673] Building CXX object tools/clang/tools/libclang/CMakeFiles/libclang.dir/CXLoadedDiagnostic.cpp.o
6073.149 [526/10/4674] Linking CXX executable bin/clang-offload-bundler
6074.816 [525/10/4675] Building CXX object tools/clang/tools/amdgpu-arch/CMakeFiles/amdgpu-arch.dir/AMDGPUArch.cpp.o
6075.576 [524/10/4676] Building CXX object tools/clang/tools/amdgpu-arch/CMakeFiles/amdgpu-arch.dir/AMDGPUArchByKFD.cpp.o
FAILED: tools/clang/tools/amdgpu-arch/CMakeFiles/amdgpu-arch.dir/AMDGPUArchByKFD.cpp.o 
/usr/local/clang-17.0.2/bin/clang++ -DGTEST_HAS_RTTI=0 -DLLVM_BUILD_STATIC -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_LARGE_FILE_API -D_XOPEN_SOURCE=700 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/tools/clang/tools/amdgpu-arch -I/home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/llvm-project/clang/tools/amdgpu-arch -I/home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/llvm-project/clang/include -I/home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/tools/clang/include -I/home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/build/include -I/home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/llvm-project/llvm/include -mcmodel=large -fPIC -Werror -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 -fno-common -Woverloaded-virtual -Wno-nested-anon-types -O3 -DNDEBUG -std=c++17  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -MD -MT tools/clang/tools/amdgpu-arch/CMakeFiles/amdgpu-arch.dir/AMDGPUArchByKFD.cpp.o -MF tools/clang/tools/amdgpu-arch/CMakeFiles/amdgpu-arch.dir/AMDGPUArchByKFD.cpp.o.d -o tools/clang/tools/amdgpu-arch/CMakeFiles/amdgpu-arch.dir/AMDGPUArchByKFD.cpp.o -c /home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/llvm-project/clang/tools/amdgpu-arch/AMDGPUArchByKFD.cpp
/home/powerllvm/powerllvm_env/aix-ppc64/clang-ppc64-aix/llvm-project/clang/tools/amdgpu-arch/AMDGPUArchByKFD.cpp:58:9: error: ignoring return value of function declared with 'nodiscard' attribute [-Werror,-Wunused-result]
   58 |         Line.drop_while([](char C) { return std::isspace(C); });
      |         ^~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
6077.385 [524/9/4677] Building CXX object tools/clang/tools/libclang/CMakeFiles/libclang.dir/CXStoredDiagnostic.cpp.o
6077.696 [524/8/4678] Building CXX object tools/clang/tools/amdgpu-arch/CMakeFiles/amdgpu-arch.dir/AMDGPUArchByHIP.cpp.o
6077.714 [524/7/4679] Building CXX object tools/clang/tools/libclang/CMakeFiles/libclang.dir/CXString.cpp.o
6079.528 [524/6/4680] Building CXX object tools/clang/tools/libclang/CMakeFiles/libclang.dir/CXSourceLocation.cpp.o
6081.109 [524/5/4681] Building CXX object tools/clang/tools/libclang/CMakeFiles/libclang.dir/CXType.cpp.o
6095.893 [524/4/4682] Building CXX object tools/clang/tools/libclang/CMakeFiles/libclang.dir/Rewrite.cpp.o
6096.515 [524/3/4683] Building CXX object tools/clang/tools/libclang/CMakeFiles/libclang.dir/Indexing.cpp.o
6096.830 [524/2/4684] Linking CXX executable bin/clang-scan-deps
6102.648 [524/1/4685] Building CXX object tools/clang/tools/libclang/CMakeFiles/libclang.dir/CXExtractAPI.cpp.o
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/116651