[llvm] Replace deprecated aligned_storage with aligned byte array (#94169)

`std::aligned_storage` is deprecated with C++23, see
[here](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p1413r3.pdf).

This replaces the usages of `std::aligned_storage` within llvm (only one
in ADT and one in Support) with an aligned `std::byte` array.
I will provide patches for other subcomponents as well.