[clang] [clang][ASTImporter] Remove type from ImportedTypes cache on Decl import failure (PR #214008)

[via cfe-commits]

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@@ -10038,6 +10038,13 @@ Expected<Decl *> ASTImporter::Import(Decl *FromD) {
       auto *ToD = CreatedToD;
       ImportedDecls.erase(Pos);
 
+      // Also scrub the imported type mapping, if applicable. Import(Type*) can
+      // cache a type mapping to a declaration that ultimately fails.
+      if (const auto *FromTD = dyn_cast<TagDecl>(FromD))
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guillem-bartrina-sonarsource wrote:

@balazske My mistake, it actually doesn't work. `TagDecl::getTypeForDecl` is deleted, and `TypeDecl::getTypeForDecl` explicitly asserts `assert(!isa<TagDecl>(this))`.

https://github.com/llvm/llvm-project/pull/214008