[clang] [clang][modules] Track Included Files Per Submodule (PR #170215)

[Qiongsi Wu via cfe-commits]

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@@ -1376,6 +1376,8 @@ void Preprocessor::makeModuleVisible(Module *M, SourceLocation Loc,
             << Message;
       });
 
+  CurSubmoduleState->IncludedFiles.insert_range(M->Includes);
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qiongsiwu wrote:

Strangely (on the surface), all the test cases I am playing around with has this as a no-op (no new modules are every added by this line of code, and removing it is just fine). I am taking a closer look. 

https://github.com/llvm/llvm-project/pull/170215