[llvm] [DWARF] Add support for DW_TAG_template_alias for template aliases (PR #88943)

[Stephen Tozer via llvm-commits]

https://github.com/SLTozer approved this pull request.

Does this patch also need to add handling for `DW_TAG_template_alias` in `llvm/lib/DWARFLinker/Parallel/`? I see similar tags like `DW_TAG_typedef` are handled there in a few files, but I'm not sure if that's either unnecessary or separate work. Other than that this looks fine to me, given the amount of discussion this has already had on the previous PR (which looks to have ended in approval).

https://github.com/llvm/llvm-project/pull/88943