[llvm] [BOLT][binary-analysis] Add initial pac-ret gadget scanner (PR #122304)

[Kristof Beyls via llvm-commits]

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@@ -2022,6 +2022,8 @@ let Predicates = [HasPAuthLR] in {
     //                              opcode2, opcode,   asm
     def AUTIASPPCr : SignAuthOneReg<0b00001, 0b100100, "autiasppcr">;
     def AUTIBSPPCr : SignAuthOneReg<0b00001, 0b100101, "autibsppcr">;
+  }
+  let Defs = [X17], Uses = [X15, X16, X17] in {
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kbeyls wrote:

This bug fix in the description of which registers instructions {PAC|AUT}I{A|B}171615 read and write should be upstreamed in a separate PR.

https://github.com/llvm/llvm-project/pull/122304