[clang] [analyzer] Fix uninitialized base class with initializer list when ctor is not declared in the base class (#70464) (PR #70792)

[Balazs Benics via cfe-commits]

steakhal wrote:

I wanted to highlight that this PR resolved a bunch of open issues, namely: #61919, #59493, #54533
Thank you!

So I think we should mention this in the release notes for clang-18 in some way. I'll keep this in mind.

https://github.com/llvm/llvm-project/pull/70792