[llvm] [Support] Add clang tooling generated explicit visibility macros (PR #113097)

[Saleem Abdulrasool via llvm-commits]

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@@ -654,7 +655,7 @@ struct OptionValue<cl::boolOrDefault> final
 };
 
 template <>
-struct OptionValue<std::string> final : OptionValueCopy<std::string> {
+struct LLVM_ABI OptionValue<std::string> final : OptionValueCopy<std::string> {
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compnerd wrote:

Are these specializations marked as `extern template`?

https://github.com/llvm/llvm-project/pull/113097