[llvm] [llvm-exegesis][AArch64] Disable pauth and ldgm as unsupported instructions fixed (PR #136868)

[Tulio Magno Quites Machado Filho via llvm-commits]

tuliom wrote:

We started to see this new test crashing when running on real aarch64:

```
FAIL: LLVM :: tools/llvm-exegesis/AArch64/skip_unsupported_instructions.s (52758 of 56744)
******************** TEST 'LLVM :: tools/llvm-exegesis/AArch64/skip_unsupported_instructions.s' FAILED ********************
Exit Code: 139

Command Output (stderr):
--
/builddir/build/BUILD/llvm-21.0.0_pre20250505.ged2f89fa00c784-build/llvm-project-ed2f89fa00c784c6a4290955fb2c68dea033fe59/llvm/redhat-linux-build/bin/llvm-exegesis -mcpu=neoverse-v2 -mode=latency --opcode-name=AUTIA --benchmark-phase=assemble-measured-code 2>&1 | /builddir/build/BUILD/llvm-21.0.0_pre20250505.ged2f89fa00c784-build/llvm-project-ed2f89fa00c784c6a4290955fb2c68dea033fe59/llvm/redhat-linux-build/bin/FileCheck /builddir/build/BUILD/llvm-21.0.0_pre20250505.ged2f89fa00c784-build/llvm-project-ed2f89fa00c784c6a4290955fb2c68dea033fe59/llvm/test/tools/llvm-exegesis/AArch64/skip_unsupported_instructions.s --check-prefix=CHECK-AUTIA # RUN: at line 6
+ /builddir/build/BUILD/llvm-21.0.0_pre20250505.ged2f89fa00c784-build/llvm-project-ed2f89fa00c784c6a4290955fb2c68dea033fe59/llvm/redhat-linux-build/bin/llvm-exegesis -mcpu=neoverse-v2 -mode=latency --opcode-name=AUTIA --benchmark-phase=assemble-measured-code
+ /builddir/build/BUILD/llvm-21.0.0_pre20250505.ged2f89fa00c784-build/llvm-project-ed2f89fa00c784c6a4290955fb2c68dea033fe59/llvm/redhat-linux-build/bin/FileCheck /builddir/build/BUILD/llvm-21.0.0_pre20250505.ged2f89fa00c784-build/llvm-project-ed2f89fa00c784c6a4290955fb2c68dea033fe59/llvm/test/tools/llvm-exegesis/AArch64/skip_unsupported_instructions.s --check-prefix=CHECK-AUTIA
/builddir/build/BUILD/llvm-21.0.0_pre20250505.ged2f89fa00c784-build/llvm-project-ed2f89fa00c784c6a4290955fb2c68dea033fe59/llvm/redhat-linux-build/test/tools/llvm-exegesis/AArch64/Output/skip_unsupported_instructions.s.script: line 2: 412142 Segmentation fault      (core dumped) /builddir/build/BUILD/llvm-21.0.0_pre20250505.ged2f89fa00c784-build/llvm-project-ed2f89fa00c784c6a4290955fb2c68dea033fe59/llvm/redhat-linux-build/bin/llvm-exegesis -mcpu=neoverse-v2 -mode=latency --opcode-name=AUTIA --benchmark-phase=assemble-measured-code 2>&1
     412143 Done                    | /builddir/build/BUILD/llvm-21.0.0_pre20250505.ged2f89fa00c784-build/llvm-project-ed2f89fa00c784c6a4290955fb2c68dea033fe59/llvm/redhat-linux-build/bin/FileCheck /builddir/build/BUILD/llvm-21.0.0_pre20250505.ged2f89fa00c784-build/llvm-project-ed2f89fa00c784c6a4290955fb2c68dea033fe59/llvm/test/tools/llvm-exegesis/AArch64/skip_unsupported_instructions.s --check-prefix=CHECK-AUTIA

```

I've only seen this failing in CPUs where paca and pacg are available.
Any idea what could be causing this crash?

https://github.com/llvm/llvm-project/pull/136868