[lld] [lld][AArch64][ELF][PAC] Support AUTH relocations and AUTH ELF marking (PR #72714)

[Fangrui Song via llvm-commits]

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@@ -398,6 +399,10 @@ void AArch64::relocate(uint8_t *loc, const Relocation &rel,
   case R_AARCH64_PREL64:
     write64(loc, val);
     break;
+  case R_AARCH64_AUTH_ABS64:
+    checkIntUInt(loc, val, 32, rel);
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MaskRay wrote:

`checkIntUInt` can be an `assert(isInt<32>(val))` thanks to `isInt<32>(sym.getVA(addend))`

https://github.com/llvm/llvm-project/pull/72714