[clang] [NFC][Clang][Docs] Update Pointer Authentication documentation (PR #152596)

[Oliver Hunt via cfe-commits]

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@@ -47,16 +47,16 @@ This document serves four purposes:
 - It documents several language extensions that are useful on targets using
   pointer authentication.
 
-- It will eventually present a theory of operation for the security mitigation,
-  describing the basic requirements for correctness, various weaknesses in the
-  mechanism, and ways in which programmers can strengthen its protections
-  (including recommendations for language implementors).
+- It presents a theory of operation for the security mitigation, describing the
+  basic requirements for correctness, various weaknesses in the mechanism, and
+  ways in which programmers can strengthen its protections (including
+  recommendations for language implementors).
 
-- It will eventually document the language ABIs currently used for C, C++,
-  Objective-C, and Swift on arm64e, although these are not yet stable on any
-  target.
+- It documents the language ABIs currently used for C, C++, and Objective-C
+  on arm64e.
----------------
ojhunt wrote:

Clarified this is the stable abi for arm64e platform specifically.

https://github.com/llvm/llvm-project/pull/152596