[clang] [llvm] [clang][docs] Migrate AttributeReference to markdown (PR #215631)

[Reid Kleckner via llvm-commits]

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@@ -10205,11 +10189,9 @@ def NoTrivialAutoVarInitDocs : Documentation {
   let Category = DocCatDecl;
   let Content = [{
 The `__declspec(no_init_all)` attribute disables the automatic initialization that the
-[-ftrivial-auto-var-init][-ftrivial-auto-var-init] flag would have applied to locals in a marked function, or instances of
+[-ftrivial-auto-var-init](https://clang.llvm.org/docs/ClangCommandLineReference.html#cmdoption-clang-ftrivial-auto-var-init) flag would have applied to locals in a marked function, or instances of
 a marked type. Note that this attribute has no effect for locals that are automatically initialized
-without the [-ftrivial-auto-var-init][-ftrivial-auto-var-init] flag.
-
-[-ftrivial-auto-var-init]: ClangCommandLineReference.html#cmdoption-clang-ftrivial-auto-var-init
+without the [-ftrivial-auto-var-init](https://clang.llvm.org/docs/ClangCommandLineReference.html#cmdoption-clang-ftrivial-auto-var-init) flag.
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rnk wrote:

It is, it happened because the auto-translated relative html file link didn't work out of the box, and this was the agentic repair.

I decided to take this opportunity to fix all the references to https?://clang.llvm.org/docs in this file. It expanded scope a bit and required adding labels to LanguageExtensions.html, but it felt worth doing.

https://github.com/llvm/llvm-project/pull/215631