[llvm] Add const check (PR #181190)

[via llvm-commits]

DeanSturtevant1 wrote:

I have a local fix that basically restores the previous code as a second constructor. Passes tests.

    template <
        typename C,
        typename = std::enable_if_t<
            std::conjunction_v<
                std::is_convertible<
                    decltype(std::declval<const C &>().data()) *, T *const *>,
                std::is_integral<decltype(std::declval<const C &>().size())>>,
            void>>
    /*implicit*/ constexpr MutableArrayRef(const C &V) : ArrayRef<T>(V) {}

https://github.com/llvm/llvm-project/pull/181190