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

[Aaron Ballman via cfe-commits]

https://github.com/AaronBallman commented:

(Some feedback, I've not had the chance to do a thorough review of all the parsing changes though.)

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