TestSuite: display at least something for test cases with no checks.

So the user is better able to guess where the problem is.
Containers: test that we are able to subscript rvalue Array.

Apparently not. Not because this is disabled for rvalues, but because of
ambiguous overload. Dammit.
Containers: remove Array::operator*() const& and const&& overloads.

They are in fact ambiguous and thus they don't solve anything. The test
is now able to compile again.