[clang] [clang-tools-extra] [Clang] Add __type_list_dedup builtin to deduplicate types in template arguments (PR #106730)

[Utkarsh Saxena via cfe-commits]

https://github.com/usx95 commented:

We also need documentation explaining the new builtin.
Can you also add ReleaseNotes. 

https://github.com/llvm/llvm-project/pull/106730