[clang] [Clang] Implement P2280R4 Using unknown pointers and references in constant expressions (PR #95474)

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https://github.com/cor3ntin commented:

Thanks a lot Shafik!

I like the direction, it looks less complex than i thought it would be
I agree with @frederick-vs-ja that some diagnostics seem to have regressed.
Maybe a variable should not treated as constexpr-unknown if it's not within its lifetime

I'd like you to go over all the related issues we have (including the ones we closed for duplication), to make sure they work as expected. i think they make up for a good corpus of unit tests

We will need changelog / status page update

Just to point it out, there are a few unresolved core issues

https://cplusplus.github.io/CWG/issues/2740.html
https://cplusplus.github.io/CWG/issues/2633.html


https://github.com/llvm/llvm-project/pull/95474