[clang] [clang] Reject 'auto' storage class with type specifier in C++ (PR #166004)

[Shafik Yaghmour via cfe-commits]

shafik wrote:

I am going to be at the wg21 meeting next week, so I may not have a chance to look at this.

https://github.com/llvm/llvm-project/pull/166004