[clang] [Clang] Fix __is_array returning true for zero-sized arrays (PR #86652)

[Jonathan Wakely via cfe-commits]

jwakely wrote:

As I've just commented at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114479 the `__is_array` intrinsic exists to optimize `std::is_array` and so should match its existing behaviour. If you want to change the behaviour of `std::is_array` then please do so via an LWG issue, e.g. requesting clarification of the behaviour for `T[0]`.

An optimization to speed up compilation of `std::is_array` should not dictate its behaviour.


https://github.com/llvm/llvm-project/pull/86652