[clang] [clang] Cleanup IncludeLocMap (PR #106241)

[Ilya Biryukov via cfe-commits]

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@@ -350,6 +350,7 @@ void SourceManager::clearIDTables() {
   LastLineNoContentCache = nullptr;
   LastFileIDLookup = FileID();
 
+  IncludedLocMap.clear();
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ilya-biryukov wrote:

Is there a way to write a unit test checking this behavior?

SourceManager should be relatively easy to mock, I think it'd be useful to write one.

https://github.com/llvm/llvm-project/pull/106241