[lld] [clang-tools-extra] [llvm] [clang] [lld][AArch64][ELF][PAC] Support AUTH relocations and AUTH ELF marking (PR #72714)

[Fangrui Song via cfe-commits]

================
@@ -543,7 +553,8 @@ class RelocationBaseSection : public SyntheticSection {
   static bool classof(const SectionBase *d) {
     return SyntheticSection::classof(d) &&
            (d->type == llvm::ELF::SHT_RELA || d->type == llvm::ELF::SHT_REL ||
-            d->type == llvm::ELF::SHT_RELR);
+            d->type == llvm::ELF::SHT_RELR ||
+            d->type == llvm::ELF::SHT_AARCH64_AUTH_RELR);
----------------
MaskRay wrote:

`SHT_AARCH64_AUTH_RELR` needs a `emachine` check.

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