[llvm] [llvm-exegesis][AArch64] Disable pauth and ldgm as unsupported instructions (PR #132346)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-gcc-ubuntu` running on `sie-linux-worker3` while building `llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/174/builds/15884

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
8.030 [90/12/138] Linking CXX executable unittests/tools/llvm-cfi-verify/CFIVerifyTests
8.046 [90/11/139] Linking CXX executable tools/clang/unittests/Sema/SemaTests
8.181 [90/10/140] Linking CXX executable unittests/Transforms/Utils/UtilsTests
8.291 [90/9/141] Linking CXX executable tools/clang/unittests/Tooling/Syntax/SyntaxTests
8.517 [90/8/142] Linking CXX executable unittests/Transforms/Scalar/ScalarTests
8.531 [90/7/143] Linking CXX executable unittests/Analysis/AnalysisTests
8.646 [90/6/144] Linking CXX executable unittests/IR/IRTests
8.820 [90/5/145] Linking CXX executable unittests/Passes/Plugins/PluginsTests
8.946 [90/4/146] Linking CXX executable bin/clang-tidy
10.560 [90/3/147] Building CXX object tools/llvm-exegesis/lib/AArch64/CMakeFiles/LLVMExegesisAArch64.dir/Target.cpp.o
FAILED: tools/llvm-exegesis/lib/AArch64/CMakeFiles/LLVMExegesisAArch64.dir/Target.cpp.o 
/opt/ccache/bin/g++ -DGTEST_HAS_RTTI=0 -DLLVM_BUILD_STATIC -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/tools/llvm-exegesis/lib/AArch64 -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/tools/llvm-exegesis/lib/AArch64 -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/include -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/include -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/lib/Target/AArch64 -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/lib/Target/AArch64 -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-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wno-misleading-indentation -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -std=c++17 -MD -MT tools/llvm-exegesis/lib/AArch64/CMakeFiles/LLVMExegesisAArch64.dir/Target.cpp.o -MF tools/llvm-exegesis/lib/AArch64/CMakeFiles/LLVMExegesisAArch64.dir/Target.cpp.o.d -o tools/llvm-exegesis/lib/AArch64/CMakeFiles/LLVMExegesisAArch64.dir/Target.cpp.o -c /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/tools/llvm-exegesis/lib/AArch64/Target.cpp
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/tools/llvm-exegesis/lib/AArch64/Target.cpp: In member function ‘virtual const char* llvm::exegesis::{anonymous}::ExegesisAArch64Target::getIgnoredOpcodeReasonOrNull(const llvm::exegesis::LLVMState&, unsigned int) const’:
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/llvm/tools/llvm-exegesis/lib/AArch64/Target.cpp:195:17: error: ‘PR_PAC_SET_ENABLED_KEYS’ was not declared in this scope
  195 |       if (prctl(PR_PAC_SET_ENABLED_KEYS,
      |                 ^~~~~~~~~~~~~~~~~~~~~~~
15.235 [90/2/148] Building CXX object lib/CodeGen/AsmPrinter/CMakeFiles/LLVMAsmPrinter.dir/AsmPrinter.cpp.o
16.253 [90/1/149] Building CXX object lib/LTO/CMakeFiles/LLVMLTO.dir/LTO.cpp.o
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/132346