[llvm-exegesis][AArch64] Disable pauth and ldgm as unsupported instructions (#132346)
[llvm-exegesis][AArch64] Disable pauth and ldgm as unsupported
instructions.
Skipping AUT and LDGM opcode variants which currently throws "illegal
instruction".
- Checking opcodes specifically for LDGM and AUT opcode instruction
variants.
- Gracefully exiting with " : Unsupported opcode:
isPointerAuth/isUncheckedAccess"
- Added corresponding test cases to check exit message.