[clang] [clang-tools-extra] Reapply "[Clang][Sema] Diagnose class member access expressions naming non-existent members of the current instantiation prior to instantiation in the absence of dependent base classes (#84050)" (PR #90152)

[via cfe-commits]

zmodem wrote:

> @zmodem Fixed in 3191e0b

Thanks!

In the meantime, we're finding a number of legitimate bugs with this. Pretty cool :)

https://github.com/llvm/llvm-project/pull/90152