llvm-project

8b7263ba - [clang] CTAD: use index and depth to retrieve template parameter for TemplateParamsReferencedInTemplateArgumentList (#98013)

[clang] CTAD: use index and depth to retrieve template parameter for TemplateParamsReferencedInTemplateArgumentList (#98013) As described in https://github.com/llvm/llvm-project/issues/90209#issuecomment-2135972202, Clang may not preserve enough information during template argument deduction. This can result in a merely canonical `TemplateTypeParmType` with a null `Decl`, leading to an incomplete template parameter list for the synthesized deduction guide. This patch addresses the issue by using the index and depth information to retrieve the corresponding template parameter, rather than relying on `TTP->getDecl()`. Fixes #90209