[clang] [AArch64][PAC][clang][ELF] Support PAuth ABI core info (PR #85235)

[Fangrui Song via cfe-commits]

================
@@ -0,0 +1,59 @@
+// RUN: %clang --target=aarch64-linux -S -emit-llvm -o - \
----------------
MaskRay wrote:

We prefer `%clang_cc1` for codegen tests. `%clang` is not used in clang/test/Driver

https://github.com/llvm/llvm-project/pull/85235