[llvm] [llvm] annotate interfaces in llvm/Support for DLL export (PR #136014)

[Saleem Abdulrasool via llvm-commits]

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@@ -41,7 +42,7 @@ class format_object_base {
   const char *Fmt;
   ~format_object_base() = default; // Disallow polymorphic deletion.
   format_object_base(const format_object_base &) = default;
-  virtual void home(); // Out of line virtual method.
+  LLVM_ABI virtual void home(); // Out of line virtual method.
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compnerd wrote:

Nit: this should be called `anchor` as per the LLVM style.

https://github.com/llvm/llvm-project/pull/136014