[clang] [clang][PAC] ptrauth_qualifier and ptrauth_intrinsic should only be available on Darwin (PR #153912)

[Oliver Hunt via cfe-commits]

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@@ -147,8 +147,8 @@ FEATURE(type_sanitizer, LangOpts.Sanitize.has(SanitizerKind::Type))
 FEATURE(thread_sanitizer, LangOpts.Sanitize.has(SanitizerKind::Thread))
 FEATURE(dataflow_sanitizer, LangOpts.Sanitize.has(SanitizerKind::DataFlow))
 FEATURE(scudo, LangOpts.Sanitize.hasOneOf(SanitizerKind::Scudo))
-FEATURE(ptrauth_intrinsics, LangOpts.PointerAuthIntrinsics)
-EXTENSION(ptrauth_qualifier, LangOpts.PointerAuthIntrinsics)
+FEATURE(ptrauth_intrinsics, LangOpts.PointerAuthIntrinsics && Target.getTriple().isOSDarwin())
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ojhunt wrote:

both of these are clearly identical so I figured making them both darwin only given __PTRAUTH__ serves the purpose for everything

https://github.com/llvm/llvm-project/pull/153912