[clang] [C++26] Implement P2752R3 'Static storage for braced initializers' (PR #197458)

[Yihan Wang via cfe-commits]

yronglin wrote:

Thanks for the review! 

> I don't think you can separate the initializer backing array check from the string literal check. All three categories of non-unique object (string literal, init list backing array, array template parameter) can overlap with each other.  e.g. `static_assert(std::initializer_list<char>{'h','e','l','l','o','\0'}.begin() != "hello");` is ill-formed.

Sorry, I might misunderstood, https://godbolt.org/z/T56cs3P73, this case seems not overlapped in runtime. 



https://github.com/llvm/llvm-project/pull/197458