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

[Fangrui Song via cfe-commits]

================
@@ -1,5 +1,37 @@
+// RUN: %clang -### -c --target=aarch64 %s 2>&1 | FileCheck %s --check-prefix NONE
+// NONE: "-cc1"
+// NONE-NOT: "-fptrauth-
+
 // RUN: %clang -### -c --target=aarch64 -fno-ptrauth-intrinsics -fptrauth-intrinsics %s 2>&1 | FileCheck %s --check-prefix=INTRIN
 // INTRIN: "-cc1"{{.*}} "-fptrauth-intrinsics"
 
-// RUN: not %clang -### -c --target=x86_64 -fptrauth-intrinsics %s 2>&1 | FileCheck %s --check-prefix=ERR
-// ERR: error: unsupported option '-fptrauth-intrinsics' for target '{{.*}}'
+// RUN: %clang -### -c --target=aarch64 -fno-ptrauth-calls -fptrauth-calls %s 2>&1 | FileCheck %s --check-prefix=CALL
----------------
MaskRay wrote:

I think there is some value separating tests for codegen but the value is largely diminished for driver.
For driver, the code looks like ` Args.addOptInFlag(CmdArgs, options::OPT_fptrauth_returns,
                    options::OPT_fno_ptrauth_returns);`. We don't repeat `OPT_fptrauth_returns` twice, so it's very difficult to make a typo mistake...

So for driver, I'd hope that some grouping is made. If that's extra trouble to you, you can submit this as is and I will simplify it a bit.

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