[clangd] Implicit destructors not recorded as reference

Currently clangd’s call hierarchy and reference don’t include destructors, making the analysis incomplete, for example: https://github.com/llvm/llvm-project/issues/157876

While there is no actual position for destructor, I think it is reasonable to be at the same location of the corresponding constructor because it is decided there. I am new to clang AST but I think the information can be infered from it. Just found https://github.com/llvm/llvm-project/pull/166110. Currently I am looking into `clang-tools-extra/clangd/index/SymbolCollector.cpp`, not sure whether in the right direction.

But I am also unsure whether adding destructor will break existing rules. Need help.

Start by reading clang-tools-extra/clangd/index/SymbolCollector.cpp and the related discussion in issue 157876, then compare the behavior described with pull request 166110. Determine how implicit destructors could be represented at the corresponding constructor location without breaking existing reference and call-hierarchy rules; done means destructor references appear in both analyses consistently.

Written by the indexing model from the issue text.