[clang] [Clang][Docs] Add documentation for -Wfortify-source (PR #224111)

[Venkatesh Srinivasan via cfe-commits]

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@@ -1897,7 +1897,35 @@ def CrossTURemarks : DiagGroup<"ctu-remarks">;
 
 def CTADMaybeUnsupported : DiagGroup<"ctad-maybe-unsupported">;
 
-def FortifySource : DiagGroup<"fortify-source", [FormatOverflow, FormatTruncation]>;
+def FortifySource : DiagGroup<"fortify-source", [FormatOverflow, FormatTruncation]> {
+  code Documentation = [{
+Warns at compile time when calls to standard C library or POSIX functions have
+provably out-of-bounds destination buffers or invalid constant arguments,
+modeled after [`_FORTIFY_SOURCE`](https://www.gnu.org/software/libc/manual/html_node/Source-Fortification.html)
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venk-ks wrote:

Fixed in 52d50f1 — updated the link to https://sourceware.org/glibc/manual/latest/html_node/Source-Fortification.html (since gnu.org now redirects deep links to the root glibc manual page).

https://github.com/llvm/llvm-project/pull/224111