[clang] [llvm] [HLSL][RootSignature] Implement initial parsing of the descriptor table clause params (PR #133800)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `openmp-offload-sles-build-only` running on `rocm-worker-hw-04-sles` while building `clang,llvm` at step 5 "compile-openmp".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/140/builds/21478

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

```
Step 5 (compile-openmp) failure: build (failure)
...
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/include/clang/Basic/PointerAuthOptions.h:70:18: warning: ‘clang::PointerAuthSchema::TheKind’ is too small to hold all values of ‘enum class clang::PointerAuthSchema::Kind’
   Kind TheKind : 2;
                  ^
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/include/clang/Basic/PointerAuthOptions.h:74:58: warning: ‘clang::PointerAuthSchema::SelectedAuthenticationMode’ is too small to hold all values of ‘enum class clang::PointerAuthenticationMode’
   PointerAuthenticationMode SelectedAuthenticationMode : 2;
                                                          ^
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/include/clang/Basic/PointerAuthOptions.h:75:39: warning: ‘clang::PointerAuthSchema::DiscriminationKind’ is too small to hold all values of ‘enum class clang::PointerAuthSchema::Discrimination’
   Discrimination DiscriminationKind : 2;
                                       ^
13.764 [1973/32/5155] Building CXX object tools/clang/lib/Parse/CMakeFiles/obj.clangParse.dir/ParseHLSLRootSignature.cpp.o
FAILED: tools/clang/lib/Parse/CMakeFiles/obj.clangParse.dir/ParseHLSLRootSignature.cpp.o 
ccache /usr/bin/c++ -DCLANG_EXPORTS -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Itools/clang/lib/Parse -I/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/lib/Parse -I/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/include -Itools/clang/include -Iinclude -I/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-uninitialized -Wno-nonnull -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wno-comment -Wno-misleading-indentation -fdiagnostics-color -ffunction-sections -fdata-sections -fno-common -Woverloaded-virtual -fno-strict-aliasing -O3 -DNDEBUG  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -std=c++1z -MD -MT tools/clang/lib/Parse/CMakeFiles/obj.clangParse.dir/ParseHLSLRootSignature.cpp.o -MF tools/clang/lib/Parse/CMakeFiles/obj.clangParse.dir/ParseHLSLRootSignature.cpp.o.d -o tools/clang/lib/Parse/CMakeFiles/obj.clangParse.dir/ParseHLSLRootSignature.cpp.o -c /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/lib/Parse/ParseHLSLRootSignature.cpp
In file included from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/include/clang/Parse/ParseHLSLRootSignature.h:23:0,
                 from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/lib/Parse/ParseHLSLRootSignature.cpp:9:
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/include/llvm/Frontend/HLSL/HLSLRootSignature.h:42:12: error: declaration of ‘llvm::hlsl::rootsig::Register llvm::hlsl::rootsig::DescriptorTableClause::Register’ [-fpermissive]
   Register Register;
            ^~~~~~~~
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/include/llvm/Frontend/HLSL/HLSLRootSignature.h:28:8: error: changes meaning of ‘Register’ from ‘struct llvm::hlsl::rootsig::Register’ [-fpermissive]
 struct Register {
        ^~~~~~~~
13.770 [1973/31/5156] Linking CXX static library lib/libclangAST.a
13.861 [1973/30/5157] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaCoroutine.cpp.o
In file included from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/include/clang/AST/Type.h:31:0,
                 from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/include/clang/AST/DeclarationName.h:16,
                 from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/include/clang/AST/DeclBase.h:19,
                 from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/include/clang/AST/Decl.h:20,
                 from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/lib/Sema/CoroutineStmtBuilder.h:16,
                 from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/lib/Sema/SemaCoroutine.cpp:16:
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/include/clang/Basic/PointerAuthOptions.h:70:18: warning: ‘clang::PointerAuthSchema::TheKind’ is too small to hold all values of ‘enum class clang::PointerAuthSchema::Kind’
   Kind TheKind : 2;
                  ^
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/include/clang/Basic/PointerAuthOptions.h:74:58: warning: ‘clang::PointerAuthSchema::SelectedAuthenticationMode’ is too small to hold all values of ‘enum class clang::PointerAuthenticationMode’
   PointerAuthenticationMode SelectedAuthenticationMode : 2;
                                                          ^
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/include/clang/Basic/PointerAuthOptions.h:75:39: warning: ‘clang::PointerAuthSchema::DiscriminationKind’ is too small to hold all values of ‘enum class clang::PointerAuthSchema::Discrimination’
   Discrimination DiscriminationKind : 2;
                                       ^
13.861 [1973/29/5158] Building AMDGPUGenDAGISel.inc...
13.918 [1973/28/5159] Building CXX object tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaCUDA.cpp.o
In file included from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/include/clang/AST/Type.h:31:0,
                 from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/include/clang/AST/DeclarationName.h:16,
                 from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/include/clang/AST/DeclBase.h:19,
                 from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/include/clang/AST/ExternalASTSource.h:18,
                 from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/include/clang/AST/Redeclarable.h:16,
                 from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/include/clang/Sema/SemaCUDA.h:18,
                 from /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/lib/Sema/SemaCUDA.cpp:13:
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/clang/include/clang/Basic/PointerAuthOptions.h:70:18: warning: ‘clang::PointerAuthSchema::TheKind’ is too small to hold all values of ‘enum class clang::PointerAuthSchema::Kind’
   Kind TheKind : 2;
                  ^

```

</details>

https://github.com/llvm/llvm-project/pull/133800