[llvm] llvm: Add missing `LLVM_ABI` annotations (PR #171629)

[Fabrice de Gans via llvm-commits]

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@@ -25,11 +25,12 @@ enum class KCFIHashAlgorithm { xxHash64, FNV1a };
 KCFIHashAlgorithm parseKCFIHashAlgorithm(StringRef Name);
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Steelskin wrote:

I am only tagging by actual usage. This does not seem to be currently used by anything outside of core LLVM so it is not tagged. I can add it if you want, though.

https://github.com/llvm/llvm-project/pull/171629