[clang-tools-extra] [clang-tidy] Fix loading clang-tidy as a Clang frontend plugin (PR #221961)

[Zeyi Xu via cfe-commits]

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@@ -0,0 +1 @@
+clang_analyzerAPIVersionString
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zeyi2 wrote:

Similar to [SampleAnalyzerPlugin.exports](https://github.com/llvm/llvm-project/blob/2449bae16b32b994282263be4cf1ece9441032f3/clang/lib/Analysis/plugins/SampleAnalyzer/SampleAnalyzerPlugin.exports#L1-L2).

https://github.com/llvm/llvm-project/pull/221961