LWG-4113 Disallow `has_unique_object_representations<Incomplete[]>`

LWG-4113 Disallow has_unique_object_representations<Incomplete[]>

We need to report this to:

• C1XX
• Clang
• EDG

so they can reject this code:

C:\Temp>type meow.cpp

#include <print>
#include <type_traits>
using namespace std;

struct Incomplete;

int main() {
    println("{}", has_unique_object_representations_v<Incomplete[]>);
}

C:\Temp>cl /EHsc /nologo /W4 /std:c++latest /MTd /Od meow.cpp && meow
meow.cpp
false

C:\Temp>clang-cl /EHsc /nologo /W4 /std:c++latest /MTd /Od meow.cpp && meow
false

C:\Temp>cl /EHsc /nologo /W4 /std:c++latest /MTd /Od /c /BE meow.cpp
meow.cpp

C:\Temp>

Use the included C++ source as meow.cpp and run the shown cl, clang-cl, and /BE command lines. Check whether each of C1XX, Clang, and EDG rejects has_unique_object_representations_v<Incomplete[]>; done means reporting the observed behavior to the listed implementations.