[llvm] Revert "[llvm-exegesis][AArch64] Disable pauth and ldgm as unsupported instructions fixed (#136868)" (PR #142382)

[Tulio Magno Quites Machado Filho via llvm-commits]

tuliom wrote:

Copying some folks from PR #136868 :
@lakshayk-nv , @boomanaiden154 , @abhilash1910

This commit is still causing issues in `LLVM :: tools/llvm-exegesis/AArch64/all-opcodes.test`.
I'm suggesting to revert the commit until a final fix is merged.
Maybe via #138643 ?

https://github.com/llvm/llvm-project/pull/142382