[clang] [Clang][Sema] Diagnose function/variable templates that shadow their own template parameters (PR #78274)

[Erich Keane via cfe-commits]

erichkeane wrote:

> @erichkeane I don't think I can add reviewers [without write access to the repo](https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/requesting-a-pull-request-review) unfortunately

I've not seen others have that problem, but perhaps?  Perhaps it is time to apply for write access: https://llvm.org/docs/DeveloperPolicy.html#obtaining-commit-access

https://github.com/llvm/llvm-project/pull/78274