[llvm] [ThinLTO] Use a set rather than a map to track exported ValueInfos. (PR #97360)

[Teresa Johnson via llvm-commits]

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@@ -818,10 +817,8 @@ static void computeImportForFunction(
           // Since definition takes precedence over declaration for the same VI,
           // try emplace <VI, declaration> pair without checking insert result.
           // If insert doesn't happen, there must be an existing entry keyed by
-          // VI.
-          if (ExportLists)
-            (*ExportLists)[DeclSourceModule].try_emplace(
-                VI, GlobalValueSummary::Declaration);
+          // VI. Note `ExportLists` only keeps track of definitions so VI won't
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teresajohnson wrote:

Maybe "only keeps track of exports due to imported definitions" ?

https://github.com/llvm/llvm-project/pull/97360