[clang] [llvm] Update llvm::Registry to work for LLVM shared library builds on windows (PR #109024)

[Aaron Ballman via cfe-commits]

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@@ -189,19 +190,23 @@
 #define LLVM_TEMPLATE_ABI __declspec(dllimport)
 #define LLVM_EXPORT_TEMPLATE
 #endif
+#define LLVM_ABI_EXPORT __declspec(dllexport)
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AaronBallman wrote:

I think this is subtle enough that we may need some documentation comments explaining when and how someone should use this. (Most reviewers aren't going to be well-versed in how shared libraries work on Windows.)

https://github.com/llvm/llvm-project/pull/109024