[clang] [clang][Dependency Scanning] Report What a Module Exports during Scanning (PR #137421)

[Cyndy Ishida via cfe-commits]

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@@ -115,6 +115,15 @@ struct ModuleID {
   }
 };
 
+struct ExtendedModuleID {
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cyndyishida wrote:

For case 1. 
i'd argue that 
`for (const auto &Info : ClangModuleDeps)` is less readable than 
`for (const auto &[ID, isExported] : ClangModuleDeps)`

For case 3, that makes sense, but I don't know that it's a strong reason unless there's an obvious use case for extending. It seems like what that vector holds should generally be lightweight. 

https://github.com/llvm/llvm-project/pull/137421