[clang] [clang][AST] Fix end location of DeclarationNameInfo on instantiated methods (PR #92654)

[Balazs Benics via cfe-commits]

steakhal wrote:

> nit: add a note in `clang/docs/ReleaseNotes.rst`

Thanks. Added. Let me know if it's in the right section. @hokein

https://github.com/llvm/llvm-project/pull/92654