[clang] [Clang] Distinguish expanding-packs-in-place cases for SubstTemplateTypeParmTypes (PR #114220)

[Matheus Izvekov via cfe-commits]

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@@ -4205,6 +4205,7 @@ SubstTemplateTypeParmType::SubstTemplateTypeParmType(
 
   SubstTemplateTypeParmTypeBits.Index = Index;
   SubstTemplateTypeParmTypeBits.PackIndex = PackIndex ? *PackIndex + 1 : 0;
+  SubstTemplateTypeParmTypeBits.ExpandPacksInPlace = ExpandPacksInPlace;
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mizvekov wrote:

ExpandPacksInPlace should only ever be true if there is a PackIndex. Can we enforce that here, and other places which are relevant, like profiling?

https://github.com/llvm/llvm-project/pull/114220