[lld] [lld][AArch64][ELF][PAC] Support `.relr.auth.dyn` section (PR #87635)

[Daniil Kovalev via llvm-commits]

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@@ -428,6 +428,19 @@ void AArch64::relocate(uint8_t *loc, const Relocation &rel,
   case R_AARCH64_PREL64:
     write64(loc, val);
     break;
+  case R_AARCH64_AUTH_ABS64:
+    // If val is wider than 32 bits, the relocation must have been moved from
+    // .relr.auth.dyn to .rela.dyn, and the addend write is not needed.
+    //
+    // If val fits in 32 bits, we have two potential scenarios:
+    // * True RELR: Write the 32-bit `val`
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kovdan01 wrote:

Added, see e68efcf46ebf0abdeec9f1fd5ed6a14e51e07e42

https://github.com/llvm/llvm-project/pull/87635