[clang] [Clang] add emit -Wignored-base-class-qualifiers diagnostic for cv-qualified base classes (PR #132116)

[Lyle Dean via cfe-commits]

lyledean1 wrote:

Thanks for the review @AaronBallman , I've updated the PR from your comments and the CI has passed - is this good to merge now? 

https://github.com/llvm/llvm-project/pull/132116