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

[Tulio Magno Quites Machado Filho via llvm-commits]

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@@ -12,12 +12,6 @@
 #if defined(__aarch64__) && defined(__linux__)
 #include <linux/prctl.h> // For PR_PAC_* constants
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tuliom wrote:

@abhilash1910 I believe that would require to also revert 36850a028d149467cafd2702bc0c2587f6b71cce and 5dc3cd0ee40c00d9fb542488fa5a54ff70273112 because they depend on this header.

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